Diabetes Care, Vol 16, Issue 1 144-149, Copyright © 1993 by American Diabetes Association
Coronary heart disease risk factors in morbidly obese women with normal glucose tolerance
HA Barakat, N Mooney, K O'Brien, S Long, PG Khazani, W Pories and JF Caro
Department of Biochemistry, School of Medicine, East Carolina University, Greenville, North Carolina 27858-4354.
OBJECTIVE--To examine if the risk for CHD increases progressively with
increases in the BMI of normoglycemic, hyperinsulinemic, morbidly obese
women (BMI > or = 35 kg/m2). RESEARCH DESIGN AND METHODS--Insulin
sensitivity was evaluated by calculating an ISI following an OGTT. There
was a significant linear relationship between ISI and BMI fitted by two
straight lines intersecting at a point corresponding to a BMI of 29.7 +/-
1.5 kg/m2. Significant linear relationships between insulin sensitivity and
BMI were obtained below and above this breakpoint. Similarly, a breakpoint
for the relation between dBP and BMI corresponding to a BMI > or = 33.7
+/- 3.4 kg/m2 was obtained. Significant linear relationships between BMI
and plasma fasting glucose, triglyceride, cholesterol, HDL cholesterol,
sBP, or dBP were not observed in the women with a BMI > 35 kg/m2.
RESULTS--Compared with lean (BMI < 27) women of similar age, the
morbidly obese patients appear to be at a higher risk for CHD. This is
suggested by statistically significant increases in fasting insulin (mean
+/- SD; 187 +/- 137 vs. 64.2 +/- 16.2 pM) and triglyceride levels (128 +/-
78.1 vs. 73 +/- 25 mg/dl), sBP (132 +/- 114 vs. 104 +/- 15.8) and dBP (84
+/- 72 vs. 67 +/- 2.1 mmHg), and decreases in HDL cholesterol (1.03 +/-
0.44 vs. 1.29 +/- 0.82 mM) and apo A-I (91 +/- 55 vs. 122 +/- 35 mg/dl)
concentrations. CONCLUSIONS--It appears that there may be a threshold of
body mass up to which insulin sensitivity is associated with CHD risk.
Above this threshold, there does not appear to be a progressive increase in
the risk factors for CHD with increases in BMI.