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Significant effects of diacylglycerol on body fat and lipid metabolism in patients on hemodialysis
ARTICLE IN PRESS Clinical Nutrition (2004) 23, 1122–1126
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ORIGINAL ARTICLE
Significant effects of diacylglycerol on body fat and lipid metabolism in patients on hemodialysis T. Teramotoa, H. Watanabeb, K. Itoc, Y. Omatac, T. Furukawac, K. Shimodad, M. Hoshinoc, T. Nagaob,*, S. Naitob a
Department of Internal Medicine, Teikyo University School of Medicine, Itabashi-ku, Tokyo 173-8605, Japan b Biological Science Laboratories, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan c Seisyokai Kikukawabashi Clinic, Tokyo, Japan d Seisyokai Hijiribashi Clinic, Tokyo, Japan Received 18 September 2003; accepted 16 February 2004
KEYWORDS Diacylglycerol; Hemodialysis; Abdominal fat; Serum lipid; Dietary fat
Summary Aims: The long-term effects of dietary diacylglycerol (DAG) on body fat and lipid metabolism were studied in patients undergoing hemodialysis (HD). Methods: Ten patients (seven males, three females) ranging in age from 40 to 64 years were enrolled. During the test period, 9.8 g of DAG was ingested per day for 3 months. Results: Body mass index did not change throughout the study. The abdominal fat area measured by CT scan decreased significantly at 3 months, and increased significantly 3 months after completion of the DAG ingestion period. The serum composition of very low-density lipoprotein (VLDL) decreased significantly at 3 months and high-density lipoprotein (HDL) increased significantly at 3 months; these were determined using polyacrylamide gel electrophoresis. Serum lipoprotein (a) decreased significantly at 3 months. Conclusions: Our study showed that 3-month ingestion of DAG reduced the amount of abdominal fat and improved serum lipid profiles in free-living HD patients. & 2004 Elsevier Ltd. All rights reserved.
Introduction Lipid abnormalities are common in patients on hemodialysis (HD).1 It has been suggested that these abnormalities are related to the development of cardiovascular disorders.2,3 Hypertriglyceridemia with low HDL-cholesterol, which might be *Corresponding author. Tel.: þ 81-285-68-7435; fax þ 81-28568-7495. E-mail address: [email protected] (T. Nagao).
associated with altered lipoprotein lipase (LPL) activity,4 is frequently observed in patients on HD. In uremic patients, LPL activity is decreased in adipose tissue5 and in postheparin plasma.4 Furthermore, insulin resistance is more remarkable in these patients, because of the removal of insulin by the kidney6 and daily consumption of high carbohydrate and fat.7 As a consequence, triglyceride-rich lipoproteins such as intermediate density lipoproteins (IDL) or remnant particles resulting from the catabolism of very low-density
0261-5614/$ - see front matter & 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.clnu.2004.02.005
ARTICLE IN PRESS Significant effects of diacylglycerol on body fat and lipid metabolism in patients on hemodialysis
lipoproteins (VLDL) and chylomicrons accumulate in patients with HD. As abdominal adiposity is associated with a deteriorating serum lipid profile and insulin resistance in patients with HD,8,9 alimentary therapy to avoid accumulation of abdominal fat is necessary. Diacylglycerol (DAG) is a component of various edible oils (e.g., olive oil) accounting for up to 5% of the total lipid content. Recently, the nutritional benefit of DAG in lipid metabolism in comparison with triacylglycerols (TAG) was reported.10–20 In particular, DAG is an edible oil that suppresses the accumulation of abdominal fat compared with TAG of the same fatty acid composition evaluated in a double-blind controlled study in healthy humans.13,19 The purpose of the present study was to examine whether DAG, when administered as cooking oil to HD patients, reduces the abdominal fat content as compared to TAG.
Materials and methods Experimental lipids DAG was prepared by esterifying glycerol with fatty acids from soybean oil using 1,3-specific lipase and purifying by silicic acid chromatography.21 Ninety percent of the total fatty acids in the DAG oil used in this study are present as 1,3-DAG and 1,2-DAG isomers at a ratio of 7:3, while less than 10% of the total fatty acids were TAG. The fatty acid compositions of test oil were described as follows: [C14:0 (0.11%), C16:0 (3.04%), C18:0 (0.96%), C18:1 (28.24%), C18:2 (59.12%), and C18:3(7.71%)]. The
Table 1
1123
combustion energy of DAG, measured using a bomb calorimeter, was approximately 9 kcal/g (Japan Food Research Laboratories, Tokyo, Japan).22
Subjects Ten uremic patients (seven males, three females) at Seisyokai Kikukawabashi Clinic (Tokyo, Japan) and Hijiribashi Clinic (Tokyo, Japan), ranging in age from 40 to 64 (average 53.8) years, participated in the study after giving informed consent. They were treated with HD three times a week and were clinically stable. The origins of chronic renal failure were chronic glomerulonephritis in six patients, diabetes mellitus in two patients, chronic renal failure in one patient, and polycystic kidney disease in one patient. The duration of HD was 1.2–22.7 (average 8.6) years. The patients’ demographics are summarized in Table 1. Venous fasting blood samples were drawn before heparinization at the time of routine dialytic therapy after an overnight fast (12–14 h). After confirming that the values of two measurements with an interval of 1 month were stable, the values of the second measurements were adopted as the initial values.
Measurement Daily intake of gross energy, total fat, and total protein was calculated from the 3-day diet questionnaires of subjects before and after the 3-month DAG ingestion period. Abdominal fat was measured by computerized tomography (CT) scan at the umbilicus (TCT-300, Toshiba Medical Co., Ltd.). From the CT images,
Characteristics of subjects.
Patient no.
Gender (Male/ Female)
Age (year)
Height (m)
Dry weight (kg)
BMI (kg/m2) Duration of Etiology of hemodialysis renal impairmentn (year)
1 2 3 4 5 6 7 8 9 10 Mean
Male Male Male Male Male Male Male Female Female Female -
51 55 60 40 42 49 62 55 64 60 53.8
1.72 1.72 1.68 1.61 1.72 1.64 1.70 1.49 1.56 1.55 1.64
62.0 69.2 60.0 57.0 78.0 52.0 58.5 47.2 44.7 47.3 57.6
21.0 23.4 21.3 22.0 26.4 19.3 20.2 21.3 18.4 19.7 21.3
3.5 1.2 2.0 2.8 14.4 14.1 17.0 4.1 3.7 22.7 8.6
CRF CGN DM CGN CGN CGN CGN DM PKD CGN F
n CRF: chronic renal failure; DM: noninsulin dependent diabetes mellitus; CGN: chronic glomerulonephritis; PKD: polycystic kidney disease.
ARTICLE IN PRESS 1124
visceral fat area, subcutaneous fat area, and total fat area (the sum of the former two) were measured using the method of Tokunaga et al.23 Serum triacylglycerol and total cholesterol were determined enzymatically. Serum lipoprotein (a) [Lp(a)] was determined using the method of Cazzoalto et al.24 The composition of lipoproteins in the serum was measured by polyacrylamide gel electrophoresis.25 The quantitation of individual fractions was accomplished by scanning densitometry after the gel was stained with reagents that dye all the composition lipids. VLDL, LDL, IDL, and HDL values were expressed as a percentage of the peak height of each lipoprotein compared to the sum of peak heights of all the lipoproteins.
Study design This clinical trial of the effects of DAG on abdominal fat and lipid metabolism was performed with respect to the principles of the Helsinki Declaration. All patients were asked to use the test oil for daily cooking at home for 3 months (DAG ingestion period). At 0, 3 and 5 months, fasting blood samples were drawn before heparinization at the time of routine dialytic therapy. The subjects underwent CT scanning of the umbilical level at 0, 3 and 6 months. Patients were advised to avoid excessive drinking and gluttony. Medication was not changed during the study. Body weight was measured before and after each dialysis, the postdialytic body weight used as the dry-weight. Body mass index (BMI) was calculated using the dry weight (kg) divided by the square of the height (m).
Statistical analysis The means of all data are presented with their standard error (means7SE). The statistical analysis of differences was performed using a paired t-test.
Results The amount of DAG ingested during the test period was 9.8 g per day according to the 3-day dietary records. The amounts of total calorie, fat, and protein ingested before and after the 3-month DAG ingestion period are shown in Table 2. The amount of total calorie and fat increased significantly from the values before the DAG ingestion period. The amount of total protein during the DAG ingestion period was similar to that before.
T. Teramoto et al.
Table 2 Calculation of daily intake of energy, protein, and fat at baseline and at 3 months into test period. Baseline
3 Months
Total energy 18947132 (100) 21137137nn (100) (kcal) Protein (g) 7173 (15.0) 7575 (14.1) Fat (g) 6175 (28.9) 7976nn (33.6) Significantly different from the initial value: nP o 0.05, nn P o 0.01. Values are means7SE (n ¼ 10). Percentage of the total energy value is given in parentheses.
As there was no change in the dry-weight of patients, BMI did not change at the end of the DAG ingestion period. As shown in Table 3, the subcutaneous fat area did not change significantly in the study period. The visceral and total fat area decreased significantly at 3 months (at the end of the DAG ingestion period) compared to the initial values, and increased significantly at 6 months (at 3 months after the DAG ingestion period) compared to the 3 months’ values. At 6 months, the values returned to levels that were not significantly different from the initial values. As shown in Table 4, the serum Lp(a) concentration decreased significantly at 3 months (at the end of the DAG ingestion period) compared to the initial values. Furthermore, it did not increase at 5 months (at 2 months after the DAG ingestion period) compared to the 3 months’ values. Serum triacylglycerol, total cholesterol and insulin concentration did not change significantly during the study period. The serum lipoprotein composition determined by polyacrylamide gel electrophoresis is also shown in Table 4. Serum VLDL composition decreased significantly at 3 months (at the end of the DAG ingestion period) compared to the initial values. Serum HDL composition increased significantly at 3 months (at the end of the DAG ingestion period) compared to the initial values. Serum LDL and IDL compositions did not change significantly in the study period.
Discussion The effects of DAG on body fat and lipid metabolism were investigated in patients on HD. In this study, we did not impose any restrictions on the total calorie and total fat intake. As a result, these
ARTICLE IN PRESS Significant effects of diacylglycerol on body fat and lipid metabolism in patients on hemodialysis
1125
Table 3 Effect of diacylglycerol on abdominal fat areas in the umbilicus as measured by CT scan and on dry weight.
Subcutaneous fat area (cm2) Visceral fat area (cm2) Total fat area (cm2) Dry weight (kg)
Baseline
3 Months
6 Months
115.4714.4 (100)
108.8715.2 (95.475.0)
111.1714.7 (97.173.9) [107.271.9]
129.4715.6 (100)
117.9718.8n (89.174.0)
129.4718.7xx (98.172.5) [111.473.6]
244.8722.4 (100)
226.9726.8n (91.073.3)
240.5726.2xx (97.172.6) [102.671.8]
57.873.4 (100.070.4)
57.773.5 (99.670.6) [99.670.6]
57.873.3 (100)
Significantly different from the initial value: P o 0.05, P o 0.01. Significantly different from the value at 3 months: x P o 0.05, xx P o 0.01. Values are means 7 SE (n ¼ 10). Percentage of the initial value is given in parentheses. Percentage of the value at 3 months is given in brackets. n
nn
Table 4 Effect of diacylglycerol on serum lipids, Lp(a) and insulin concentration and on serum lipoproteins composition. Baseline
3 Months
5 Months
Triacylglycerol (mg/dl ) Total cholesterol (mg/dl ) Lp(a) (mg/dl ) Insulin (mU / ml )
165720 (100) 183711 (100) 28.677.2 (100) 771 (100)
151720 (93.577) 188712 (103.073.4) 24.775.9 n (87.878.1) 771 (101.2712.3)
155721 (94.979.0) [101.575.8] 18479 (101.773.4) [99.172.9] 25.576.3 n (86.576.2 ) [102.578.7] 771 (119.5725.0 ) [127.2725.9]
VLDL LDL HDL IDL
30.672.7 24.273.0 30.171.1 15.171.9
26.572.7nn (86.474.5) 26.772.4 (115.076.1) 32.471.3 n (108.073.1) 14.471.9 (95.774.5)
29.173.3 27.272.2 30.772.0 13.075.2
(100) (100) (100) (100)
(98.6710.2) [113.0711.0] (119.578.8) [104.877.6] (101.575.2) [94.073.9] (88.076.7) [91.575.0]
Significantly different from the initial value: nP o 0.05, nnP o 0.01. Values are means 7 SE (n ¼ 10). Percentage of the initial value is given in parentheses. Percentage of the value at 3 months is given in brackets.
values increased significantly from the initial values. Nevertheless, abdominal fat area, Lp(a) concentration and VLDL composition in serum lipoproteins decreased significantly during the DAG ingestion period as compared to the initial values. These results suggested that DAG ingestion might improve the accumulation of body fat and lipid metabolism in patients on HD. The DAG used in this study consisted of 1,3-DAG and 1,2-DAG isomers at a ratio of 7:3. Energy values of the DAG and the TAG, measured by bomb calorimeter, were almost the same.22 In this study, the amount of DAG ingested during the test period was 9.8 g per day according to the 3-day dietary records. We previously reported that DAG, in contrast to TAG, suppresses both body weight and regional fat deposition including visceral and hepatic fat, which are causative of various pathologic conditions in a double-blind controlled study
using healthy but near-obese male volunteers.13 The dose of DAG in that study was 10 g per day, which is approximately equal to the average daily consumption of cooking oil in Japan. These results indicated that the patients on HD show suppressed visceral fat accumulation in DAG ingestion, whose amounts are almost the same as that of the healthy volunteers ingested and also approximately equal to the average daily consumption of cooking oil in Japan. Ingestion of DAG for 3 months improved the lipoprotein composition (decreased serum VLDL levels and increased serum HDL levels) and reduced the visceral fat area. It is well known that obesity is frequently associated with increased plasma VLDL and reduced plasma HDL levels.26 These results suggested that DAG ingestion might improve the lipoprotein composition due to the decrease of visceral fat in patient on HD.
ARTICLE IN PRESS 1126
Beil et al. reported that dietary fish oil decreased Lp(a) in primary hypertriglyceridemia, and that this effect depended on the amount of omega-3 fatty acids or the amount of fish oil.27 Hornstra et al. reported that a dietary palm oil decreased serum Lp(a) in normocholesterolemic volunteers.28 In the present study, the significant decrease in the serum Lp(a) concentration after DAG ingestion might be a consequence of the decreased hepatic fat content, as we reported previously.13 The results of the present study indicated that 3month ingestion of DAG reduces the accumulation of visceral fat and improves the serum lipid profiles in free-living HD patients, and also suggested that DAG oil might be useful in patients on HD; alimentary therapy is necessary to avoid the accumulation of visceral fat.
References 1. Chan MK, Varghese Z, Morhead JF. Lipid abnormalities in uremia, dialysis and transplantation. Kidney Int 1981;19:625–37. 2. Linder A, Charra B, Sherrard DJ, Scribner BH. Accelerated atherosclerosis in prolonged maintenance hemodialysis. N Engl J Med 1974;290:697–701. 3. Burton BT, Kureger KK, Bryan FA. National registry of longterm dialysis patients. JAMA 1971;218:718–22. 4. Chan MK, Persaud J, Varghese Z, Moorhead JF. Pathogenic roles of post-heparin lipases in lipid abnormalities in hemodialysis patients. Kidney Int 1984;25:812–8. 5. Persson B. Lipoprotein lipase activity of human adipose tissue in health and in some diseases with hyperlipidemia as a common feature. Acta Med Scand 1973;193:457–62. 6. Westervelt FB. Insulin effect in uremia. J Lab Clin Med 1969;74:79–84. 7. Panzetta G, Maschio G. Dietary problems of the dialysis patient. Blood Purif 1985;3:63–74. 8. Lee P, O’Neal D, Murphy B, Best J. The role of abdominal adiposity and insulin resistance in dyslipidemia of chronic renal failure. Am J Kidney Dis 1997;29:54–65. 9. Odamaki M, Furuya R, Ohkawa S, et al. Altered abdominal fat distribution and its association with the serum lipid profile in nondiabetic hemodialysis patients. Nephrol Dial Transplant 1999;14:2427–32. 10. Hara K, Onizawa K, Honda H, Otsuji K, Ide T, Murata M. Dietary diacylglycerol-dependent reduction in serum triacylglycerol concentration in rats. Ann Nutr Metab 1993;37:185–91. 11. Murata M, Hara K, Ide T. Alteration by diacylglycerols of the transport and fatty acid composition of lymph chylomicrons in rats. Biosci Biotech Biochem 1994;58:1416–9.
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12. Murata M, Ide T, Hara K. Reciprocal responses to dietary diacylglycerol of hepatic enzymes of fatty acid synthesis and oxidation in the rat. Br J Nutr 1997;77:107–21. 13. Nagao T, Watanabe H, Goto N, et al. Dietary diacylglycerol suppresses accumulation of body fat in men in a double blind controlled trial. J Nutr 2000;130:792–7. 14. Murase T, Mizuno T, Omachi T, et al. Dietary diacylglycerol suppresses high fat and high sucrose diet-induced body fat accumulation in C57BL/6J mice. J Lipid Res 2001;42: 372–8. 15. Taguchi H, Watanabe H, Onizawa K, et al. Double-blind controlled study on the effects of dietary diacylglycerol on postprandial serum and chylomicron triacylglycerol responses in healthy humans. J Am Coll Nutr 2001;19: 789–96. 16. Yamamoto K, Asakawa H, Tokunaga K, et al. Long-term ingestion of dietary diacylglycerol lowers serum triacylglycerol in type II diabetic patients with hypertriglyceridemia. J Nutr 2001;131:3204–7. 17. Tada N, Watanabe H, Matsuo N, Tokimitsu I, Okazaki M. Dynamics of postprandial remnant-like lipoprotein particles in serum after loading of diacylglycerols. Clin Chim Acta 2001;311:109–17. 18. Murase T, Aoki M, Wakisaka T, Hase T, Tokimitsu I. Antiobesity effect of dietary diacylglycerol in C57BL/6J mice: dietary diacylglycerol stimulates intestinal lipid metabolism. J Lipid Res 2002;43:1312–9. 19. Maki KC, Davidson MH, Tsushima R, et al. Consumption of diacylglycerol oil as part of a reduced-energy diet enhances loss of body weight and fat in comparison with consumption of a triacylglycerol control oil. Am J Clin Nutr 2002;76:1230–6. 20. Tada N, Yoshida H. Diacylglycerol on lipid metabolism. Curr Opin Lipidol 2003;14:29–33. 21. Huge-Jensen B, Galluzzo DR, Jensen RG. Studies on free and immobilized lipases from Mucor miehei. JAOCS 1988;65:905–10. 22. Taguchi H, Nagao T, Watanabe H, et al. Energy value and digestibility of dietary oil containing mainly 1,3-diacylglycerol are similar to those of triacylglycerol. Lipids 2001;36:379–82. 23. Tokunaga K, Matsuzasa Y, Ishikawa K, Tarui S. A novel technique for the determination of body fat by computed tomography. Int J Obes 1983;7:437–45. 24. Cazzoalto G, Praksch G, Green S, Kostner GM. The determination of lipoprotein Lp(a) by rate and endpoint nephelometry. Clin Chim Acta 1983;135:203–8. 25. Hatch FT. Practical methods for plasma lipoprotein analysis. Adv Lipid Res 1968;6:1–68. 26. Carmena R, Ascaso JF, Real JT. Impact of obesity in primary hyperlipidemias. Nutr Metab Cardiovasc Dis 2001;11:354–9. 27. Beil FU, Terres M, Orgass M, Greten H. Dietary fish oil lowers lipoprotein(a) in primary hypertriacylglyceridemia. Atherosclerosis 1991;90:95–7. 28. Hornstra G, Van Houwelingen AC, Kester ADM, Sundram K. A palm oil-enriched diet lowers serum lipoprotein (a) in normocholesterolemic volunteers. Atherosclerosis 1991;90:91–3.
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ORIGINAL ARTICLE
Significant effects of diacylglycerol on body fat and lipid metabolism in patients on hemodialysis T. Teramotoa, H. Watanabeb, K. Itoc, Y. Omatac, T. Furukawac, K. Shimodad, M. Hoshinoc, T. Nagaob,*, S. Naitob a
Department of Internal Medicine, Teikyo University School of Medicine, Itabashi-ku, Tokyo 173-8605, Japan b Biological Science Laboratories, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan c Seisyokai Kikukawabashi Clinic, Tokyo, Japan d Seisyokai Hijiribashi Clinic, Tokyo, Japan Received 18 September 2003; accepted 16 February 2004
KEYWORDS Diacylglycerol; Hemodialysis; Abdominal fat; Serum lipid; Dietary fat
Summary Aims: The long-term effects of dietary diacylglycerol (DAG) on body fat and lipid metabolism were studied in patients undergoing hemodialysis (HD). Methods: Ten patients (seven males, three females) ranging in age from 40 to 64 years were enrolled. During the test period, 9.8 g of DAG was ingested per day for 3 months. Results: Body mass index did not change throughout the study. The abdominal fat area measured by CT scan decreased significantly at 3 months, and increased significantly 3 months after completion of the DAG ingestion period. The serum composition of very low-density lipoprotein (VLDL) decreased significantly at 3 months and high-density lipoprotein (HDL) increased significantly at 3 months; these were determined using polyacrylamide gel electrophoresis. Serum lipoprotein (a) decreased significantly at 3 months. Conclusions: Our study showed that 3-month ingestion of DAG reduced the amount of abdominal fat and improved serum lipid profiles in free-living HD patients. & 2004 Elsevier Ltd. All rights reserved.
Introduction Lipid abnormalities are common in patients on hemodialysis (HD).1 It has been suggested that these abnormalities are related to the development of cardiovascular disorders.2,3 Hypertriglyceridemia with low HDL-cholesterol, which might be *Corresponding author. Tel.: þ 81-285-68-7435; fax þ 81-28568-7495. E-mail address: [email protected] (T. Nagao).
associated with altered lipoprotein lipase (LPL) activity,4 is frequently observed in patients on HD. In uremic patients, LPL activity is decreased in adipose tissue5 and in postheparin plasma.4 Furthermore, insulin resistance is more remarkable in these patients, because of the removal of insulin by the kidney6 and daily consumption of high carbohydrate and fat.7 As a consequence, triglyceride-rich lipoproteins such as intermediate density lipoproteins (IDL) or remnant particles resulting from the catabolism of very low-density
0261-5614/$ - see front matter & 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.clnu.2004.02.005
ARTICLE IN PRESS Significant effects of diacylglycerol on body fat and lipid metabolism in patients on hemodialysis
lipoproteins (VLDL) and chylomicrons accumulate in patients with HD. As abdominal adiposity is associated with a deteriorating serum lipid profile and insulin resistance in patients with HD,8,9 alimentary therapy to avoid accumulation of abdominal fat is necessary. Diacylglycerol (DAG) is a component of various edible oils (e.g., olive oil) accounting for up to 5% of the total lipid content. Recently, the nutritional benefit of DAG in lipid metabolism in comparison with triacylglycerols (TAG) was reported.10–20 In particular, DAG is an edible oil that suppresses the accumulation of abdominal fat compared with TAG of the same fatty acid composition evaluated in a double-blind controlled study in healthy humans.13,19 The purpose of the present study was to examine whether DAG, when administered as cooking oil to HD patients, reduces the abdominal fat content as compared to TAG.
Materials and methods Experimental lipids DAG was prepared by esterifying glycerol with fatty acids from soybean oil using 1,3-specific lipase and purifying by silicic acid chromatography.21 Ninety percent of the total fatty acids in the DAG oil used in this study are present as 1,3-DAG and 1,2-DAG isomers at a ratio of 7:3, while less than 10% of the total fatty acids were TAG. The fatty acid compositions of test oil were described as follows: [C14:0 (0.11%), C16:0 (3.04%), C18:0 (0.96%), C18:1 (28.24%), C18:2 (59.12%), and C18:3(7.71%)]. The
Table 1
1123
combustion energy of DAG, measured using a bomb calorimeter, was approximately 9 kcal/g (Japan Food Research Laboratories, Tokyo, Japan).22
Subjects Ten uremic patients (seven males, three females) at Seisyokai Kikukawabashi Clinic (Tokyo, Japan) and Hijiribashi Clinic (Tokyo, Japan), ranging in age from 40 to 64 (average 53.8) years, participated in the study after giving informed consent. They were treated with HD three times a week and were clinically stable. The origins of chronic renal failure were chronic glomerulonephritis in six patients, diabetes mellitus in two patients, chronic renal failure in one patient, and polycystic kidney disease in one patient. The duration of HD was 1.2–22.7 (average 8.6) years. The patients’ demographics are summarized in Table 1. Venous fasting blood samples were drawn before heparinization at the time of routine dialytic therapy after an overnight fast (12–14 h). After confirming that the values of two measurements with an interval of 1 month were stable, the values of the second measurements were adopted as the initial values.
Measurement Daily intake of gross energy, total fat, and total protein was calculated from the 3-day diet questionnaires of subjects before and after the 3-month DAG ingestion period. Abdominal fat was measured by computerized tomography (CT) scan at the umbilicus (TCT-300, Toshiba Medical Co., Ltd.). From the CT images,
Characteristics of subjects.
Patient no.
Gender (Male/ Female)
Age (year)
Height (m)
Dry weight (kg)
BMI (kg/m2) Duration of Etiology of hemodialysis renal impairmentn (year)
1 2 3 4 5 6 7 8 9 10 Mean
Male Male Male Male Male Male Male Female Female Female -
51 55 60 40 42 49 62 55 64 60 53.8
1.72 1.72 1.68 1.61 1.72 1.64 1.70 1.49 1.56 1.55 1.64
62.0 69.2 60.0 57.0 78.0 52.0 58.5 47.2 44.7 47.3 57.6
21.0 23.4 21.3 22.0 26.4 19.3 20.2 21.3 18.4 19.7 21.3
3.5 1.2 2.0 2.8 14.4 14.1 17.0 4.1 3.7 22.7 8.6
CRF CGN DM CGN CGN CGN CGN DM PKD CGN F
n CRF: chronic renal failure; DM: noninsulin dependent diabetes mellitus; CGN: chronic glomerulonephritis; PKD: polycystic kidney disease.
ARTICLE IN PRESS 1124
visceral fat area, subcutaneous fat area, and total fat area (the sum of the former two) were measured using the method of Tokunaga et al.23 Serum triacylglycerol and total cholesterol were determined enzymatically. Serum lipoprotein (a) [Lp(a)] was determined using the method of Cazzoalto et al.24 The composition of lipoproteins in the serum was measured by polyacrylamide gel electrophoresis.25 The quantitation of individual fractions was accomplished by scanning densitometry after the gel was stained with reagents that dye all the composition lipids. VLDL, LDL, IDL, and HDL values were expressed as a percentage of the peak height of each lipoprotein compared to the sum of peak heights of all the lipoproteins.
Study design This clinical trial of the effects of DAG on abdominal fat and lipid metabolism was performed with respect to the principles of the Helsinki Declaration. All patients were asked to use the test oil for daily cooking at home for 3 months (DAG ingestion period). At 0, 3 and 5 months, fasting blood samples were drawn before heparinization at the time of routine dialytic therapy. The subjects underwent CT scanning of the umbilical level at 0, 3 and 6 months. Patients were advised to avoid excessive drinking and gluttony. Medication was not changed during the study. Body weight was measured before and after each dialysis, the postdialytic body weight used as the dry-weight. Body mass index (BMI) was calculated using the dry weight (kg) divided by the square of the height (m).
Statistical analysis The means of all data are presented with their standard error (means7SE). The statistical analysis of differences was performed using a paired t-test.
Results The amount of DAG ingested during the test period was 9.8 g per day according to the 3-day dietary records. The amounts of total calorie, fat, and protein ingested before and after the 3-month DAG ingestion period are shown in Table 2. The amount of total calorie and fat increased significantly from the values before the DAG ingestion period. The amount of total protein during the DAG ingestion period was similar to that before.
T. Teramoto et al.
Table 2 Calculation of daily intake of energy, protein, and fat at baseline and at 3 months into test period. Baseline
3 Months
Total energy 18947132 (100) 21137137nn (100) (kcal) Protein (g) 7173 (15.0) 7575 (14.1) Fat (g) 6175 (28.9) 7976nn (33.6) Significantly different from the initial value: nP o 0.05, nn P o 0.01. Values are means7SE (n ¼ 10). Percentage of the total energy value is given in parentheses.
As there was no change in the dry-weight of patients, BMI did not change at the end of the DAG ingestion period. As shown in Table 3, the subcutaneous fat area did not change significantly in the study period. The visceral and total fat area decreased significantly at 3 months (at the end of the DAG ingestion period) compared to the initial values, and increased significantly at 6 months (at 3 months after the DAG ingestion period) compared to the 3 months’ values. At 6 months, the values returned to levels that were not significantly different from the initial values. As shown in Table 4, the serum Lp(a) concentration decreased significantly at 3 months (at the end of the DAG ingestion period) compared to the initial values. Furthermore, it did not increase at 5 months (at 2 months after the DAG ingestion period) compared to the 3 months’ values. Serum triacylglycerol, total cholesterol and insulin concentration did not change significantly during the study period. The serum lipoprotein composition determined by polyacrylamide gel electrophoresis is also shown in Table 4. Serum VLDL composition decreased significantly at 3 months (at the end of the DAG ingestion period) compared to the initial values. Serum HDL composition increased significantly at 3 months (at the end of the DAG ingestion period) compared to the initial values. Serum LDL and IDL compositions did not change significantly in the study period.
Discussion The effects of DAG on body fat and lipid metabolism were investigated in patients on HD. In this study, we did not impose any restrictions on the total calorie and total fat intake. As a result, these
ARTICLE IN PRESS Significant effects of diacylglycerol on body fat and lipid metabolism in patients on hemodialysis
1125
Table 3 Effect of diacylglycerol on abdominal fat areas in the umbilicus as measured by CT scan and on dry weight.
Subcutaneous fat area (cm2) Visceral fat area (cm2) Total fat area (cm2) Dry weight (kg)
Baseline
3 Months
6 Months
115.4714.4 (100)
108.8715.2 (95.475.0)
111.1714.7 (97.173.9) [107.271.9]
129.4715.6 (100)
117.9718.8n (89.174.0)
129.4718.7xx (98.172.5) [111.473.6]
244.8722.4 (100)
226.9726.8n (91.073.3)
240.5726.2xx (97.172.6) [102.671.8]
57.873.4 (100.070.4)
57.773.5 (99.670.6) [99.670.6]
57.873.3 (100)
Significantly different from the initial value: P o 0.05, P o 0.01. Significantly different from the value at 3 months: x P o 0.05, xx P o 0.01. Values are means 7 SE (n ¼ 10). Percentage of the initial value is given in parentheses. Percentage of the value at 3 months is given in brackets. n
nn
Table 4 Effect of diacylglycerol on serum lipids, Lp(a) and insulin concentration and on serum lipoproteins composition. Baseline
3 Months
5 Months
Triacylglycerol (mg/dl ) Total cholesterol (mg/dl ) Lp(a) (mg/dl ) Insulin (mU / ml )
165720 (100) 183711 (100) 28.677.2 (100) 771 (100)
151720 (93.577) 188712 (103.073.4) 24.775.9 n (87.878.1) 771 (101.2712.3)
155721 (94.979.0) [101.575.8] 18479 (101.773.4) [99.172.9] 25.576.3 n (86.576.2 ) [102.578.7] 771 (119.5725.0 ) [127.2725.9]
VLDL LDL HDL IDL
30.672.7 24.273.0 30.171.1 15.171.9
26.572.7nn (86.474.5) 26.772.4 (115.076.1) 32.471.3 n (108.073.1) 14.471.9 (95.774.5)
29.173.3 27.272.2 30.772.0 13.075.2
(100) (100) (100) (100)
(98.6710.2) [113.0711.0] (119.578.8) [104.877.6] (101.575.2) [94.073.9] (88.076.7) [91.575.0]
Significantly different from the initial value: nP o 0.05, nnP o 0.01. Values are means 7 SE (n ¼ 10). Percentage of the initial value is given in parentheses. Percentage of the value at 3 months is given in brackets.
values increased significantly from the initial values. Nevertheless, abdominal fat area, Lp(a) concentration and VLDL composition in serum lipoproteins decreased significantly during the DAG ingestion period as compared to the initial values. These results suggested that DAG ingestion might improve the accumulation of body fat and lipid metabolism in patients on HD. The DAG used in this study consisted of 1,3-DAG and 1,2-DAG isomers at a ratio of 7:3. Energy values of the DAG and the TAG, measured by bomb calorimeter, were almost the same.22 In this study, the amount of DAG ingested during the test period was 9.8 g per day according to the 3-day dietary records. We previously reported that DAG, in contrast to TAG, suppresses both body weight and regional fat deposition including visceral and hepatic fat, which are causative of various pathologic conditions in a double-blind controlled study
using healthy but near-obese male volunteers.13 The dose of DAG in that study was 10 g per day, which is approximately equal to the average daily consumption of cooking oil in Japan. These results indicated that the patients on HD show suppressed visceral fat accumulation in DAG ingestion, whose amounts are almost the same as that of the healthy volunteers ingested and also approximately equal to the average daily consumption of cooking oil in Japan. Ingestion of DAG for 3 months improved the lipoprotein composition (decreased serum VLDL levels and increased serum HDL levels) and reduced the visceral fat area. It is well known that obesity is frequently associated with increased plasma VLDL and reduced plasma HDL levels.26 These results suggested that DAG ingestion might improve the lipoprotein composition due to the decrease of visceral fat in patient on HD.
ARTICLE IN PRESS 1126
Beil et al. reported that dietary fish oil decreased Lp(a) in primary hypertriglyceridemia, and that this effect depended on the amount of omega-3 fatty acids or the amount of fish oil.27 Hornstra et al. reported that a dietary palm oil decreased serum Lp(a) in normocholesterolemic volunteers.28 In the present study, the significant decrease in the serum Lp(a) concentration after DAG ingestion might be a consequence of the decreased hepatic fat content, as we reported previously.13 The results of the present study indicated that 3month ingestion of DAG reduces the accumulation of visceral fat and improves the serum lipid profiles in free-living HD patients, and also suggested that DAG oil might be useful in patients on HD; alimentary therapy is necessary to avoid the accumulation of visceral fat.
References 1. Chan MK, Varghese Z, Morhead JF. Lipid abnormalities in uremia, dialysis and transplantation. Kidney Int 1981;19:625–37. 2. Linder A, Charra B, Sherrard DJ, Scribner BH. Accelerated atherosclerosis in prolonged maintenance hemodialysis. N Engl J Med 1974;290:697–701. 3. Burton BT, Kureger KK, Bryan FA. National registry of longterm dialysis patients. JAMA 1971;218:718–22. 4. Chan MK, Persaud J, Varghese Z, Moorhead JF. Pathogenic roles of post-heparin lipases in lipid abnormalities in hemodialysis patients. Kidney Int 1984;25:812–8. 5. Persson B. Lipoprotein lipase activity of human adipose tissue in health and in some diseases with hyperlipidemia as a common feature. Acta Med Scand 1973;193:457–62. 6. Westervelt FB. Insulin effect in uremia. J Lab Clin Med 1969;74:79–84. 7. Panzetta G, Maschio G. Dietary problems of the dialysis patient. Blood Purif 1985;3:63–74. 8. Lee P, O’Neal D, Murphy B, Best J. The role of abdominal adiposity and insulin resistance in dyslipidemia of chronic renal failure. Am J Kidney Dis 1997;29:54–65. 9. Odamaki M, Furuya R, Ohkawa S, et al. Altered abdominal fat distribution and its association with the serum lipid profile in nondiabetic hemodialysis patients. Nephrol Dial Transplant 1999;14:2427–32. 10. Hara K, Onizawa K, Honda H, Otsuji K, Ide T, Murata M. Dietary diacylglycerol-dependent reduction in serum triacylglycerol concentration in rats. Ann Nutr Metab 1993;37:185–91. 11. Murata M, Hara K, Ide T. Alteration by diacylglycerols of the transport and fatty acid composition of lymph chylomicrons in rats. Biosci Biotech Biochem 1994;58:1416–9.
T. Teramoto et al.
12. Murata M, Ide T, Hara K. Reciprocal responses to dietary diacylglycerol of hepatic enzymes of fatty acid synthesis and oxidation in the rat. Br J Nutr 1997;77:107–21. 13. Nagao T, Watanabe H, Goto N, et al. Dietary diacylglycerol suppresses accumulation of body fat in men in a double blind controlled trial. J Nutr 2000;130:792–7. 14. Murase T, Mizuno T, Omachi T, et al. Dietary diacylglycerol suppresses high fat and high sucrose diet-induced body fat accumulation in C57BL/6J mice. J Lipid Res 2001;42: 372–8. 15. Taguchi H, Watanabe H, Onizawa K, et al. Double-blind controlled study on the effects of dietary diacylglycerol on postprandial serum and chylomicron triacylglycerol responses in healthy humans. J Am Coll Nutr 2001;19: 789–96. 16. Yamamoto K, Asakawa H, Tokunaga K, et al. Long-term ingestion of dietary diacylglycerol lowers serum triacylglycerol in type II diabetic patients with hypertriglyceridemia. J Nutr 2001;131:3204–7. 17. Tada N, Watanabe H, Matsuo N, Tokimitsu I, Okazaki M. Dynamics of postprandial remnant-like lipoprotein particles in serum after loading of diacylglycerols. Clin Chim Acta 2001;311:109–17. 18. Murase T, Aoki M, Wakisaka T, Hase T, Tokimitsu I. Antiobesity effect of dietary diacylglycerol in C57BL/6J mice: dietary diacylglycerol stimulates intestinal lipid metabolism. J Lipid Res 2002;43:1312–9. 19. Maki KC, Davidson MH, Tsushima R, et al. Consumption of diacylglycerol oil as part of a reduced-energy diet enhances loss of body weight and fat in comparison with consumption of a triacylglycerol control oil. Am J Clin Nutr 2002;76:1230–6. 20. Tada N, Yoshida H. Diacylglycerol on lipid metabolism. Curr Opin Lipidol 2003;14:29–33. 21. Huge-Jensen B, Galluzzo DR, Jensen RG. Studies on free and immobilized lipases from Mucor miehei. JAOCS 1988;65:905–10. 22. Taguchi H, Nagao T, Watanabe H, et al. Energy value and digestibility of dietary oil containing mainly 1,3-diacylglycerol are similar to those of triacylglycerol. Lipids 2001;36:379–82. 23. Tokunaga K, Matsuzasa Y, Ishikawa K, Tarui S. A novel technique for the determination of body fat by computed tomography. Int J Obes 1983;7:437–45. 24. Cazzoalto G, Praksch G, Green S, Kostner GM. The determination of lipoprotein Lp(a) by rate and endpoint nephelometry. Clin Chim Acta 1983;135:203–8. 25. Hatch FT. Practical methods for plasma lipoprotein analysis. Adv Lipid Res 1968;6:1–68. 26. Carmena R, Ascaso JF, Real JT. Impact of obesity in primary hyperlipidemias. Nutr Metab Cardiovasc Dis 2001;11:354–9. 27. Beil FU, Terres M, Orgass M, Greten H. Dietary fish oil lowers lipoprotein(a) in primary hypertriacylglyceridemia. Atherosclerosis 1991;90:95–7. 28. Hornstra G, Van Houwelingen AC, Kester ADM, Sundram K. A palm oil-enriched diet lowers serum lipoprotein (a) in normocholesterolemic volunteers. Atherosclerosis 1991;90:91–3.