HIGH FASTING INSULIN LEVELS ASSOCIATED WITH LOWER RATES OF WEIGHT-GAIN IN PERSONS WITH NORMAL GLUCOSE-TOLERANCE - THE SAN-LUIS VALLEY DIABETES STUDY

OBJECTIVE: to investigate whether increased insulin resistance is asso ciated with a reduced risk of weight gain among Hispanic and non-Hispa nic white persons in Colorado. DESIGN: measurements were taken at base line and after an average of 4.3 years.SUBJECTS: 789 normal glucose to lerant subjects 20 to 74 years of age were studied. MEASUREMENTS: fast ing insulin levels were used as an indirect marker of insulin resistan ce. RESULTS: the average baseline body mass index (BMI) was 26.1 (+/- 3.6 s.d,) in men and 25.2 (+/- 4.4 s.d.) in women, The average weight change at follow-up was 0.8 kg (+/- 4.3 s.d.) in men and 1.3 kg (+/- 5 .0) in women, A doubling in initial fasting insulin was associated wit h a reduced risk of gaining 5 kg (n = 134) and 10 kg (n = 24) of weigh t in logistic regression models (OR(5kg) = 0.76, 95% CI: 0.59, 0.99 an d OR(10kg) = 0.61, 95% CI: 0.36, 1.02), Similarly, a doubling of initi al fasting insulin was associated (P = 0.006) on average with a 6.3 kg less weight gain in linear regression models, independently of initia l body weight, age, sex, ethnicity and BMI, The relation was consisten tly observed in men and women and in both ethnic groups. CONCLUSION: h igher initial fasting insulin decreases the risk of subsequent weight gain in both Hispanic and non-Hispanic white normal glucose tolerant i ndividuals similar to Pima Indians. This appears to be a common biolog ic characteristic in moderate to low as well as high risk populations for NIDDM.