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Digoxin-like immunoactivity in pregnant women with diabetes mellitus
516
A,rH-M4Y
LETIXRS TO THE EDITOR
Digoxin-like Immunoactivity
199&VOL.
9, NO.
5
in Pregnant Women With Diabetes Mellitus
In the Am&cm Journal ofHypertension (1995;6:5-ll), you published an article by authors Steven W. Graves, Kim Lincoln, Sandra L. Cook, and Ellen W. Seely entitled “Digitalis-Like Factor and Digoxin-Like Immunoreactive Factor in Diabetic Women With Preeclampsia, Transient Hypertension of Pregnancy, and Normotensive Pregnancy.“’ In this interesting clinical study, the authors document elevated levels of digitalis-like factor (DLF) and digoxin-like immunoreactive factor (DLIF) in normotensive pregnant women with insulin dependent diabetes mellitus (IDDM) and suggest hypothesis that IDDM itself affects DLF and DLIF. The authors ascribe these findings to greater sodium retention and intravascular volume expansion in pregnant women with lDDM, which it a known stimulus leading to increase in serum DLF aad DLTF. As an alternative mechanism, the authors suggest that insulin may independently and directly increase DLF and DLIF or, that insulin, which can be increased in IDDM patients as a consequence of their therapy, may act on regulators of the DLF and indirectly increase it. What was surprising for us is the comment by the authors, that “the impact of diabetes on DLF and DLIF in humans, in particular during pregnancy, has not previously been studied.” We would like to point out some of our previous work,*-5 where we investigated the relation of fasting plasma DLIF to plasma glucose and insulin response in normotensive pregnant women during a 75 g oral glucose tolerance test (OG’IT). In agreement with Graves and coworkers we have found significantly higher fasting plasma DLIF in pregnant women with gestational diabetes meliitus compared with pregnant women with normal glucose tolerance. In addition, DLIF was significantly correlated with plasma glucose and insulin response during OG’IT. Conversely, we observed in pregnant women during OGTT that the higher the fasting plasma DLIF, the worse the glucose tolerance and the greater the insulin secretion.
A difference between the study of Graves and our study is that, while Graves investigated women with IDDM on insulin therapy, we investigated pregnant
women with gestational ( “pregnancy induced” ) diabetes mellitus, who were hyperinsulinemic and did not require insulin therapy. WC highly appreciate the study of Graves and coworkers and consider it as another support for our hypothesis relating DLIF to diabetes mellitus (insulin resistance/insulin secretion).‘-” This area, however is sti:! unclear and deserves further investigation.
REFERENCES 1.
Graves SW, Lincoln K, Cook SL, Seely EW: Digitalis-
like facto: and digoxin-like immunoreactive factor in diabetic women with preeclampsia, transient hypertension of pregnancy, and normotensive pregnancy. Am J Hypertens 1995;6:5-11.
2.
Martinka E; MatdBek J, Ochodnickv M, el al: Digoxinlike immunoactivity and glucose tolerance in pregnancy. Diabetes Nutr Metab 1993;4:189-194.
3.
Martinka E, MokZi M, MatiSek J, et al: NOR?vlastnosti digoxinu podobnel imunoaktivity? (in Slovak) (New properties of dig&n-iike immunoactivity?). KliickL Biochemie a Metabolisms 1994;2:67-70.
4.
Martinka E, Mokdii M: Digoxin-like and digitoxin-like immunoactivity and glucose induced insulin secretion in pregnantwomen (abst). 15JDFCongress,November 6-11,1994,Kobe,Japan,p405.
5.
Martinka E, MahiSek J, MokPii M, et al: Dynamicke zmeny digoxinu-podobnej imunoaktivity potas oGTT u tehotnjrch Lien (in Slovak). (Dynamic changes of digoxin-like immunoactivity during CKXT in pregnant women). Bratisl Lek Listy 1993;10:526-530. EMILMARTINKA,MILAN OCHODNICW, MOKAN ANDMARIAN From the Department of Internal Medicine I, Jesenius Medical School, University of Corn&us, Martin, Slovakia.
Address correspondence and reprint requests to Dr. Emil Martinka, MD, Dept. of Interna; Medicine I, hWN, KoIl&ova 2, 036 59 iMartin, Slovakia.
A,rH-M4Y
LETIXRS TO THE EDITOR
Digoxin-like Immunoactivity
199&VOL.
9, NO.
5
in Pregnant Women With Diabetes Mellitus
In the Am&cm Journal ofHypertension (1995;6:5-ll), you published an article by authors Steven W. Graves, Kim Lincoln, Sandra L. Cook, and Ellen W. Seely entitled “Digitalis-Like Factor and Digoxin-Like Immunoreactive Factor in Diabetic Women With Preeclampsia, Transient Hypertension of Pregnancy, and Normotensive Pregnancy.“’ In this interesting clinical study, the authors document elevated levels of digitalis-like factor (DLF) and digoxin-like immunoreactive factor (DLIF) in normotensive pregnant women with insulin dependent diabetes mellitus (IDDM) and suggest hypothesis that IDDM itself affects DLF and DLIF. The authors ascribe these findings to greater sodium retention and intravascular volume expansion in pregnant women with lDDM, which it a known stimulus leading to increase in serum DLF aad DLTF. As an alternative mechanism, the authors suggest that insulin may independently and directly increase DLF and DLIF or, that insulin, which can be increased in IDDM patients as a consequence of their therapy, may act on regulators of the DLF and indirectly increase it. What was surprising for us is the comment by the authors, that “the impact of diabetes on DLF and DLIF in humans, in particular during pregnancy, has not previously been studied.” We would like to point out some of our previous work,*-5 where we investigated the relation of fasting plasma DLIF to plasma glucose and insulin response in normotensive pregnant women during a 75 g oral glucose tolerance test (OG’IT). In agreement with Graves and coworkers we have found significantly higher fasting plasma DLIF in pregnant women with gestational diabetes meliitus compared with pregnant women with normal glucose tolerance. In addition, DLIF was significantly correlated with plasma glucose and insulin response during OG’IT. Conversely, we observed in pregnant women during OGTT that the higher the fasting plasma DLIF, the worse the glucose tolerance and the greater the insulin secretion.
A difference between the study of Graves and our study is that, while Graves investigated women with IDDM on insulin therapy, we investigated pregnant
women with gestational ( “pregnancy induced” ) diabetes mellitus, who were hyperinsulinemic and did not require insulin therapy. WC highly appreciate the study of Graves and coworkers and consider it as another support for our hypothesis relating DLIF to diabetes mellitus (insulin resistance/insulin secretion).‘-” This area, however is sti:! unclear and deserves further investigation.
REFERENCES 1.
Graves SW, Lincoln K, Cook SL, Seely EW: Digitalis-
like facto: and digoxin-like immunoreactive factor in diabetic women with preeclampsia, transient hypertension of pregnancy, and normotensive pregnancy. Am J Hypertens 1995;6:5-11.
2.
Martinka E; MatdBek J, Ochodnickv M, el al: Digoxinlike immunoactivity and glucose tolerance in pregnancy. Diabetes Nutr Metab 1993;4:189-194.
3.
Martinka E, MokZi M, MatiSek J, et al: NOR?vlastnosti digoxinu podobnel imunoaktivity? (in Slovak) (New properties of dig&n-iike immunoactivity?). KliickL Biochemie a Metabolisms 1994;2:67-70.
4.
Martinka E, Mokdii M: Digoxin-like and digitoxin-like immunoactivity and glucose induced insulin secretion in pregnantwomen (abst). 15JDFCongress,November 6-11,1994,Kobe,Japan,p405.
5.
Martinka E, MahiSek J, MokPii M, et al: Dynamicke zmeny digoxinu-podobnej imunoaktivity potas oGTT u tehotnjrch Lien (in Slovak). (Dynamic changes of digoxin-like immunoactivity during CKXT in pregnant women). Bratisl Lek Listy 1993;10:526-530. EMILMARTINKA,MILAN OCHODNICW, MOKAN ANDMARIAN From the Department of Internal Medicine I, Jesenius Medical School, University of Corn&us, Martin, Slovakia.
Address correspondence and reprint requests to Dr. Emil Martinka, MD, Dept. of Interna; Medicine I, hWN, KoIl&ova 2, 036 59 iMartin, Slovakia.