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Seasonal variation of serum high density lipoprotein cholesterol levels in men
Atherosclerosis, 48 (1983) 167-172 Elsevier Scientific Publishers Ireland,
167 Ltd.
ATH 3368
Seasonal Variation of Serum High Density Lipoprotein Cholesterol Levels in Men Jun Sasaki ‘, Gengo Kumagae ‘, Teizo Sata ‘, Masaharu Shigeki Tsutsumi 2 and Kikuo Arakawa ’
Ikeda ‘,
’The Second Department of Medicine, Fukuoka Universiiy Hospital, and ’ Tsutsumi Hospital, Fukuoka (Japan) (Received 6 January, 1983) (Revised, received 14 March, 1983) (Accepted 17 March, 1983)
Summary
To determine if there are seasonal variations in serum high density lipoprotein cholesterol (HDL-C), the concentration of HDL-C was measured monthly for 12 consecutive months in 31 healthy men and 24 male inpatients with schizophrenia. In addition to HDL-C, total cholesterol (TC) and triglyceride (TG) concentrations in serum were assayed, and low density lipoprotein cholesterol (LDL-C) was estimated by calculation. Mean serum HDL-C levels of schizophrenic patients were significantly low compared with those of healthy controls, 35 + 12 and 49 + 11 mg/dl, respectively. The TC levels of schizophrenic patients were significantly higher in January and March as compared with August. The HDL-C levels in summer and autumn were significantly lower than those in winter and spring in both healthy men and schizophrenic patients. The concentration of LDL-C was significantly high in September and October as compared with April in healthy men. In patients with schizophrenia, LDL-C level seemed higher in January and March as compared with August. Key words:
HDL cholesterol - Schizophrenia
Address for correspondence: Jun Hospital, 7-45-1, Nanakuma, Jonan-ku, 0021-9150/83/$03.00
- Seasonal variation
Sasaki, M.D., Department Fukuoka 814-01, Japan.
0 1983 Elsevier Scientific
Publishers
Ireland,
of Medicine,
Ltd.
Fukuoka
University
168
Introduction HDL has been reported to be a negative risk factor for the development of premature cardiovascular disease [ 1,2]. Therefore, measurement of HDL-C has become common to assess the risk of development of heart disease, and it is now being measured in all sorts of groups from long distance runners to patients with hepatic or renal disease. HDL-C concentration is known to be influenced by a variety of factors [3], including diet, drugs, hormones and physical exercise, but little is known about its seasonal variation. In the present study, the serum concentration of TC, TG and HDL-C was quantitated in normal male adults and in patients with schizophrenia for 12 consecutive months to investigate seasonal variation. Methods The healthy adult group consisted of 31 male medical doctors aged 27-50 years old (average 35) of Fukuoka University Hospital. The patient group, all of whom had a regular and similar life style as regards diet, physical exercise, etc., consisted of 24 male inpatients with schizophrenia aged 27-54 years old (average 40), admitted to Tsutsumi Psychiatric Hospital. Patients were maintained on the same drugs, i.e. individual or combinations of phenothiazine derivatives (chlorpromazine, levomepromazine, perphenazine), that they had been receiving for 3 to 18 years (average 9 years). Fourteen out of 24 patients were receiving benzodiazepines simultaneously. There were no changes in diet, exercise or drug treatment during the study. None of the subjects had diseases known to affect lipid metabolism. Blood samples were taken monthly from March 1979 to May 1980. Blood was drawn after a standard 12-14 h overnight fast. Serum was separated by centrifugation at 3000 rpm for 15 min. Samples were stored at 4°C and analyses were carried out within 48 h. The TC and TG concentrations in serum and lipoprotein fractions were determined enzymatically [4,5]. Seronorum lipid (Nyegaard Corp., Oslo, Norway) was used for the quality control of TC. The coefficients of variation of duplicate determinations were 2.8% and 3.0% for TC and TG, respectively. The HDL-C was measured by the heparin-MnCl, precipitation method using a final concentration of manganese chloride of 92 mM [6]. The coefficient of variation of duplicate determinations was 2.6%. HDL-C of the same samples was routinely assayed at Kyushu Koseinenkin Hospital by the phosphotungstic acid-MgCl, precipitation method. The percentage difference between two laboratories for HDL-C was f2.4 mg/dl. LDL-C was calculated from the formula of LDL-C = TC (HDL-C) - TG,‘5 [8]. A two-tailed Student’s r-test was used for statistical analysis. Results Serum lipid and lipoprotein lipid levels for healthy men and male patients schizophrenia are listed in Table 1. Mean values of TC, TG and LDL-C
with were
169
TABLE
1
SERUM TIENTS
LIPIDS AND LIPOPROTEIN WITH SCHIZOPHRENIA
LIPIDS
Values are means f SD of total serum samples Healthy Age (year) Obesity index (%) Total cholesterol (mg/dl) Triglycerides (mg/dl) HDL cholesterol LDL cholesterol
IN HEALTHY
except age and obesity
men
34.5* 1.4 109 *I3 190 &32 138 +59 49 &I1 113 &29
(mg/dl) (mg/dl)
LEVELS
MEN
AND
MALE
PA-
index.
Male schizophrenics
Significance
40.6+ 7.8 112 +13 201 +37 183 k88 35 +12 131 +31
P i 0.05 P < 0.02 P
significantly higher in patients with schizophrenia as compared with healthy men. In contrast, patients with schizophrenia had a significantly decreased concentration of HDL-C. The mean serum HDL-C levels in males (healthy and schizophrenics) are shown in Fig. 1, on a monthly basis. The HDL-C level in healthy men was significantly higher in November (52 & 10 mg/dl) and December (52 &- 12 mg/dl) than in June (46 k 10 mg/dl) and September (46 f 9 mg/dl). Likewise, in schizophrenic patients, the HDL-C level was significantly higher in November (39 k 13 mg/dl), December (37 f 12 mg/dl), February (38 f 13 mg/dl), and April (38 + 11 mg/dl) than in June (30 f 10 mg/dl) and July (30 + 11 mg/dl). In healthy men, TC levels were not significantly different throughout the year (Fig. 2A), but LDL-C levels were significantly higher in September and October than those in April. The TC levels in patients with schizophrenia were significantly higher in January and March than in
‘It-----‘793
4
5
6
7
6
9
IO II
12
I
2
3
4
5
Months
Fig. 1. Monthly changes in HDL-C levels in healthy men (solid line) and male inpatients with schizophrenia (dotted line). Statistically significant monthly differences between * and ** are shown (P -c 0.05).
01
’
’
‘79.3
4
’
’
’
’
’
’
’
’
’
’
5
6
7
6
9
IO
II
12 ‘SOI
2
Molmr
g
300
-
I3
‘a E -6 ii
250-
z
200
-
z ; 3
150 K).
-
r~.~_._rl---r--_~;~.~,,~.~___*
50 0, 796
7
I 9
a
I
I
IO
II
1
I
l2’eOl
1 2
* 3
I
I
4
5
Months
Fig. 2. Monthly changes of TC (solid line) and LDL-C (dotted line) levels in healthy men and male schizophrenic patients. Statistically significant monthly differences between * and ** are shown (P < 0.05). A, healthy men; B, male schizophrenic patients.
IIIll 1 /’ \
-.
0’ ““‘~““‘~~” ‘79345676
,,’
‘!
-
9lOltl2,
2345
Months
Fig. 3. Monthly changes of triglyceride levels in healthy men (solid line) and male schizophrenic (dotted line). The difference between mean monthly values was not significant (P > 0.05).
patients
171
August (Fig. 2B). LDL-C levels were also significantly higher in January and March than in August (Fig. 2B). Monthly TG levels are shown in Fig. 3. The mean TG levels in patients with schizophrenia were significantly higher than in healthy men. No significant monthly changes in serum TG levels were observed in either healthy men or the patients with schizophrenia. Liver and renal function tests were normal and without significant seasonal variation throughout this study. Discussion Significant seasonal differences in the concentration of HDL-C were observed in both the healthy men (n = 31) and the male patients with schizophrenia (n = 24) included in the study. In both, the concentration of HDL-C was significantly higher in winter and spring than in summer and autumn. In Japan, it is usually very humid in summer and dry in winter. The decreased HDL-C levels observed in June and July coincide with the rainy season. In one cross-sectional study, a significant drop in the HDL-C level has been reported in March, with a gradual increase through May to reach peak levels in late June and early July [9]. However, that study did not last longer than 5 months. On the other hand, Mjos et al. [lo] reported from a longitudinal study that no statistically significant seasonal changes in HDL-C were observed. Reasons for the differences observed in these studies remain unknown, but geographical, environmental and ethnic differences may be responsible. Even though the mechanisms for these seasonal variations remain unknown, such variation should be taken into account in assessing HDL-C levels. TC levels have been reported to increase in spring and summer and decrease in autumn and winter, whereas TG levels did not show any significant seasonal changes [ 111. The results of the present study reveal no significant changes in the TC levels in healthy men, but male patients with schizophrenia had significantly higher TC levels between October and January as compared with July to September. It is well documented that the prolonged use of phenothiazine and related drugs can induce hypercholesterolemia [12-141. In this study, the schizophrenic patients had significantly higher TC, TG and LDL-C levels and low HDL-C levels as compared with healthy men. Do the low HDL-C levels result from the disease itself, or from drugs being administered such as phenothiazines? A small but significant decrease in HDL-C levels was reported in males treated with benzodiazepines (controls = 47.9 + 1.2, benzodiazepine users = 44.6 + 1.1 mg/dl, n = 112) whereas no significant reduction was found in females treated with the same compounds [ 151. High doses of phenothiazine and related neuroleptic drugs are reported to result in reduced plasma estrogen levels probably due to hypothalamic depression [16,17]. Therefore, it is speculated that phenothiazines decrease plasma estrogen levels, which secondarily result in the low HDL-C levels observed in these male schizophrenic patients.
172
Acknowledgement The authors wish to thank Professor Gene L. Cottam of the University for his careful reading of the paper and valuable suggestions.
of Texas
References 1 Miller, G.J. and Miller, N.F., Plasma-high density lipoprotein concentration and development of ischemic heart disease, Lancet, i (1975) 16. 2 Castelli, W., Doyle, J.T., Gordon, T., Hames, C.G., Hjortland, M.C., Hulley, S.B., Kagan, A. and Zukel, W.J., HDL cholesterol and other lipids in coronary heart disease - The Cooperative Lipoprotein Phenotyping Study, Circulation, 55 (1977) 767. 3 Narayan, K.A., Factors Influencing the Concentration of Serum High-density Lipoproteins, Marcel Dekker, Inc., New York, NY, 1981, p. 559. 4 Allain, CC., Poon, L.S., Chan, C.S., Richmond, W. and Fu, P.C., Enzymatic determination of total serum cholesterol, Clin. Chem., 20 (1974)470. im Blutserum und Gewebe. I. 5 Eggstein, M. and Kreutz, F.H., Eine neue Bestimmung der Neutralfette Mitt. (Prinzip, Durchftihrung und Besprechung der Methode), Klin. Wschr., 44 (1966) 262. 6 Warnick, G.R. and Albers, J.J., A comprehensive evaluation of the heparin-manganese precipitation procedure for estimating high density lipoprotein cholesterol, J. Lipid Res., 19 (1978) 65. 7 Sata, T. and Nishimoto, S., Personal communication. D.S., Estimation of low density lipoprotein cholesterol 8 Friedwald, W.T., Levy, RI. and Fredrickson, in plasma, without use of preparative ultracentrifuge, Clin. Chem., 18 (1972) 499. 9 Van Gent, C.M., Van der Voort, H. and Hessel, L.W., High density lipoprotein cholesterol, monthly variation and association with cardiovascular risk factors in 1000 forty-year-old Dutch citizens, Clin. Chim. Acta, 88 (1978) 155. 10 Mjos, O.D., Rao, S.N., Bjoru, L., Henden, T., Thelle, D.S., Forde, O.H. and Miller, N.E., A longitudinal study of the biological variability of plasma lipoproteins in healthy young adults, Atherosclerosis, 34 (1979) 75. 11 Shibata, S., Pathological Biochemistry, Kimpodo, Tokyo, 1977, p. 89. 12 Clark, M.L. and Johnson, P.C., Amenorrhea and elevated levels of serum cholesterol produced by trifluomethylated phenothiazine (SKF 5354-8), J. Clin. Endocrinol. Metab., 20 (1960) 641. R.E., Costiloe, J.P., Smith, C.W. and Wolf, S., 13 Clark, M.L., Ray, T.S., Paredes, A., Ragland, Chlorpromazine in women with chronic schizophrenia - The effect on cholesterol levels and cholesterol-behavior relationships, Psychosomat. Med., 29 (1967) 634. 14 Clark, M.L., Dubowski, K. and Colmore, J., The effect of chlorpromazine on serum cholesterol in chronic schizophrenic patients, Clin. Pharmacol. Ther., 11 (1970) 883. D.B., Reiland, S., Barrett-Connor, E., Mackenthun, A., Hoover, J. and 15 Wallace, R.B., Hunninghake, Wahl, P., Alterations of plasma high density lipoprotein cholesterol levels associated with consumption of selected medications, Circulation, 62 (1980) Suppl. IV-77. B., A controlled seven 16 Kline, N.S., Blair, J., Cooper, T.B., Esser, A.H., Hackett, E. and Westergaard, years study of endocrine and other indices in drug treated chronic schizophrenics, Acta Psychiat. Stand. Suppl., 206 (1968) 7. and endocrine functions, Pharmacol. Rev., 19 (1967) 25 1. 17 Wied, D. de, Chlorpromazine
167 Ltd.
ATH 3368
Seasonal Variation of Serum High Density Lipoprotein Cholesterol Levels in Men Jun Sasaki ‘, Gengo Kumagae ‘, Teizo Sata ‘, Masaharu Shigeki Tsutsumi 2 and Kikuo Arakawa ’
Ikeda ‘,
’The Second Department of Medicine, Fukuoka Universiiy Hospital, and ’ Tsutsumi Hospital, Fukuoka (Japan) (Received 6 January, 1983) (Revised, received 14 March, 1983) (Accepted 17 March, 1983)
Summary
To determine if there are seasonal variations in serum high density lipoprotein cholesterol (HDL-C), the concentration of HDL-C was measured monthly for 12 consecutive months in 31 healthy men and 24 male inpatients with schizophrenia. In addition to HDL-C, total cholesterol (TC) and triglyceride (TG) concentrations in serum were assayed, and low density lipoprotein cholesterol (LDL-C) was estimated by calculation. Mean serum HDL-C levels of schizophrenic patients were significantly low compared with those of healthy controls, 35 + 12 and 49 + 11 mg/dl, respectively. The TC levels of schizophrenic patients were significantly higher in January and March as compared with August. The HDL-C levels in summer and autumn were significantly lower than those in winter and spring in both healthy men and schizophrenic patients. The concentration of LDL-C was significantly high in September and October as compared with April in healthy men. In patients with schizophrenia, LDL-C level seemed higher in January and March as compared with August. Key words:
HDL cholesterol - Schizophrenia
Address for correspondence: Jun Hospital, 7-45-1, Nanakuma, Jonan-ku, 0021-9150/83/$03.00
- Seasonal variation
Sasaki, M.D., Department Fukuoka 814-01, Japan.
0 1983 Elsevier Scientific
Publishers
Ireland,
of Medicine,
Ltd.
Fukuoka
University
168
Introduction HDL has been reported to be a negative risk factor for the development of premature cardiovascular disease [ 1,2]. Therefore, measurement of HDL-C has become common to assess the risk of development of heart disease, and it is now being measured in all sorts of groups from long distance runners to patients with hepatic or renal disease. HDL-C concentration is known to be influenced by a variety of factors [3], including diet, drugs, hormones and physical exercise, but little is known about its seasonal variation. In the present study, the serum concentration of TC, TG and HDL-C was quantitated in normal male adults and in patients with schizophrenia for 12 consecutive months to investigate seasonal variation. Methods The healthy adult group consisted of 31 male medical doctors aged 27-50 years old (average 35) of Fukuoka University Hospital. The patient group, all of whom had a regular and similar life style as regards diet, physical exercise, etc., consisted of 24 male inpatients with schizophrenia aged 27-54 years old (average 40), admitted to Tsutsumi Psychiatric Hospital. Patients were maintained on the same drugs, i.e. individual or combinations of phenothiazine derivatives (chlorpromazine, levomepromazine, perphenazine), that they had been receiving for 3 to 18 years (average 9 years). Fourteen out of 24 patients were receiving benzodiazepines simultaneously. There were no changes in diet, exercise or drug treatment during the study. None of the subjects had diseases known to affect lipid metabolism. Blood samples were taken monthly from March 1979 to May 1980. Blood was drawn after a standard 12-14 h overnight fast. Serum was separated by centrifugation at 3000 rpm for 15 min. Samples were stored at 4°C and analyses were carried out within 48 h. The TC and TG concentrations in serum and lipoprotein fractions were determined enzymatically [4,5]. Seronorum lipid (Nyegaard Corp., Oslo, Norway) was used for the quality control of TC. The coefficients of variation of duplicate determinations were 2.8% and 3.0% for TC and TG, respectively. The HDL-C was measured by the heparin-MnCl, precipitation method using a final concentration of manganese chloride of 92 mM [6]. The coefficient of variation of duplicate determinations was 2.6%. HDL-C of the same samples was routinely assayed at Kyushu Koseinenkin Hospital by the phosphotungstic acid-MgCl, precipitation method. The percentage difference between two laboratories for HDL-C was f2.4 mg/dl. LDL-C was calculated from the formula of LDL-C = TC (HDL-C) - TG,‘5 [8]. A two-tailed Student’s r-test was used for statistical analysis. Results Serum lipid and lipoprotein lipid levels for healthy men and male patients schizophrenia are listed in Table 1. Mean values of TC, TG and LDL-C
with were
169
TABLE
1
SERUM TIENTS
LIPIDS AND LIPOPROTEIN WITH SCHIZOPHRENIA
LIPIDS
Values are means f SD of total serum samples Healthy Age (year) Obesity index (%) Total cholesterol (mg/dl) Triglycerides (mg/dl) HDL cholesterol LDL cholesterol
IN HEALTHY
except age and obesity
men
34.5* 1.4 109 *I3 190 &32 138 +59 49 &I1 113 &29
(mg/dl) (mg/dl)
LEVELS
MEN
AND
MALE
PA-
index.
Male schizophrenics
Significance
40.6+ 7.8 112 +13 201 +37 183 k88 35 +12 131 +31
P i 0.05 P < 0.02 P
significantly higher in patients with schizophrenia as compared with healthy men. In contrast, patients with schizophrenia had a significantly decreased concentration of HDL-C. The mean serum HDL-C levels in males (healthy and schizophrenics) are shown in Fig. 1, on a monthly basis. The HDL-C level in healthy men was significantly higher in November (52 & 10 mg/dl) and December (52 &- 12 mg/dl) than in June (46 k 10 mg/dl) and September (46 f 9 mg/dl). Likewise, in schizophrenic patients, the HDL-C level was significantly higher in November (39 k 13 mg/dl), December (37 f 12 mg/dl), February (38 f 13 mg/dl), and April (38 + 11 mg/dl) than in June (30 f 10 mg/dl) and July (30 + 11 mg/dl). In healthy men, TC levels were not significantly different throughout the year (Fig. 2A), but LDL-C levels were significantly higher in September and October than those in April. The TC levels in patients with schizophrenia were significantly higher in January and March than in
‘It-----‘793
4
5
6
7
6
9
IO II
12
I
2
3
4
5
Months
Fig. 1. Monthly changes in HDL-C levels in healthy men (solid line) and male inpatients with schizophrenia (dotted line). Statistically significant monthly differences between * and ** are shown (P -c 0.05).
01
’
’
‘79.3
4
’
’
’
’
’
’
’
’
’
’
5
6
7
6
9
IO
II
12 ‘SOI
2
Molmr
g
300
-
I3
‘a E -6 ii
250-
z
200
-
z ; 3
150 K).
-
r~.~_._rl---r--_~;~.~,,~.~___*
50 0, 796
7
I 9
a
I
I
IO
II
1
I
l2’eOl
1 2
* 3
I
I
4
5
Months
Fig. 2. Monthly changes of TC (solid line) and LDL-C (dotted line) levels in healthy men and male schizophrenic patients. Statistically significant monthly differences between * and ** are shown (P < 0.05). A, healthy men; B, male schizophrenic patients.
IIIll 1 /’ \
-.
0’ ““‘~““‘~~” ‘79345676
,,’
‘!
-
9lOltl2,
2345
Months
Fig. 3. Monthly changes of triglyceride levels in healthy men (solid line) and male schizophrenic (dotted line). The difference between mean monthly values was not significant (P > 0.05).
patients
171
August (Fig. 2B). LDL-C levels were also significantly higher in January and March than in August (Fig. 2B). Monthly TG levels are shown in Fig. 3. The mean TG levels in patients with schizophrenia were significantly higher than in healthy men. No significant monthly changes in serum TG levels were observed in either healthy men or the patients with schizophrenia. Liver and renal function tests were normal and without significant seasonal variation throughout this study. Discussion Significant seasonal differences in the concentration of HDL-C were observed in both the healthy men (n = 31) and the male patients with schizophrenia (n = 24) included in the study. In both, the concentration of HDL-C was significantly higher in winter and spring than in summer and autumn. In Japan, it is usually very humid in summer and dry in winter. The decreased HDL-C levels observed in June and July coincide with the rainy season. In one cross-sectional study, a significant drop in the HDL-C level has been reported in March, with a gradual increase through May to reach peak levels in late June and early July [9]. However, that study did not last longer than 5 months. On the other hand, Mjos et al. [lo] reported from a longitudinal study that no statistically significant seasonal changes in HDL-C were observed. Reasons for the differences observed in these studies remain unknown, but geographical, environmental and ethnic differences may be responsible. Even though the mechanisms for these seasonal variations remain unknown, such variation should be taken into account in assessing HDL-C levels. TC levels have been reported to increase in spring and summer and decrease in autumn and winter, whereas TG levels did not show any significant seasonal changes [ 111. The results of the present study reveal no significant changes in the TC levels in healthy men, but male patients with schizophrenia had significantly higher TC levels between October and January as compared with July to September. It is well documented that the prolonged use of phenothiazine and related drugs can induce hypercholesterolemia [12-141. In this study, the schizophrenic patients had significantly higher TC, TG and LDL-C levels and low HDL-C levels as compared with healthy men. Do the low HDL-C levels result from the disease itself, or from drugs being administered such as phenothiazines? A small but significant decrease in HDL-C levels was reported in males treated with benzodiazepines (controls = 47.9 + 1.2, benzodiazepine users = 44.6 + 1.1 mg/dl, n = 112) whereas no significant reduction was found in females treated with the same compounds [ 151. High doses of phenothiazine and related neuroleptic drugs are reported to result in reduced plasma estrogen levels probably due to hypothalamic depression [16,17]. Therefore, it is speculated that phenothiazines decrease plasma estrogen levels, which secondarily result in the low HDL-C levels observed in these male schizophrenic patients.
172
Acknowledgement The authors wish to thank Professor Gene L. Cottam of the University for his careful reading of the paper and valuable suggestions.
of Texas
References 1 Miller, G.J. and Miller, N.F., Plasma-high density lipoprotein concentration and development of ischemic heart disease, Lancet, i (1975) 16. 2 Castelli, W., Doyle, J.T., Gordon, T., Hames, C.G., Hjortland, M.C., Hulley, S.B., Kagan, A. and Zukel, W.J., HDL cholesterol and other lipids in coronary heart disease - The Cooperative Lipoprotein Phenotyping Study, Circulation, 55 (1977) 767. 3 Narayan, K.A., Factors Influencing the Concentration of Serum High-density Lipoproteins, Marcel Dekker, Inc., New York, NY, 1981, p. 559. 4 Allain, CC., Poon, L.S., Chan, C.S., Richmond, W. and Fu, P.C., Enzymatic determination of total serum cholesterol, Clin. Chem., 20 (1974)470. im Blutserum und Gewebe. I. 5 Eggstein, M. and Kreutz, F.H., Eine neue Bestimmung der Neutralfette Mitt. (Prinzip, Durchftihrung und Besprechung der Methode), Klin. Wschr., 44 (1966) 262. 6 Warnick, G.R. and Albers, J.J., A comprehensive evaluation of the heparin-manganese precipitation procedure for estimating high density lipoprotein cholesterol, J. Lipid Res., 19 (1978) 65. 7 Sata, T. and Nishimoto, S., Personal communication. D.S., Estimation of low density lipoprotein cholesterol 8 Friedwald, W.T., Levy, RI. and Fredrickson, in plasma, without use of preparative ultracentrifuge, Clin. Chem., 18 (1972) 499. 9 Van Gent, C.M., Van der Voort, H. and Hessel, L.W., High density lipoprotein cholesterol, monthly variation and association with cardiovascular risk factors in 1000 forty-year-old Dutch citizens, Clin. Chim. Acta, 88 (1978) 155. 10 Mjos, O.D., Rao, S.N., Bjoru, L., Henden, T., Thelle, D.S., Forde, O.H. and Miller, N.E., A longitudinal study of the biological variability of plasma lipoproteins in healthy young adults, Atherosclerosis, 34 (1979) 75. 11 Shibata, S., Pathological Biochemistry, Kimpodo, Tokyo, 1977, p. 89. 12 Clark, M.L. and Johnson, P.C., Amenorrhea and elevated levels of serum cholesterol produced by trifluomethylated phenothiazine (SKF 5354-8), J. Clin. Endocrinol. Metab., 20 (1960) 641. R.E., Costiloe, J.P., Smith, C.W. and Wolf, S., 13 Clark, M.L., Ray, T.S., Paredes, A., Ragland, Chlorpromazine in women with chronic schizophrenia - The effect on cholesterol levels and cholesterol-behavior relationships, Psychosomat. Med., 29 (1967) 634. 14 Clark, M.L., Dubowski, K. and Colmore, J., The effect of chlorpromazine on serum cholesterol in chronic schizophrenic patients, Clin. Pharmacol. Ther., 11 (1970) 883. D.B., Reiland, S., Barrett-Connor, E., Mackenthun, A., Hoover, J. and 15 Wallace, R.B., Hunninghake, Wahl, P., Alterations of plasma high density lipoprotein cholesterol levels associated with consumption of selected medications, Circulation, 62 (1980) Suppl. IV-77. B., A controlled seven 16 Kline, N.S., Blair, J., Cooper, T.B., Esser, A.H., Hackett, E. and Westergaard, years study of endocrine and other indices in drug treated chronic schizophrenics, Acta Psychiat. Stand. Suppl., 206 (1968) 7. and endocrine functions, Pharmacol. Rev., 19 (1967) 25 1. 17 Wied, D. de, Chlorpromazine