Changes associated with weight gain in intensive insulin therapy are similar to those seen in insulin resistance syndrome (1). However, the effect of abdominal adiposity in type 1 diabetes has been scarcely documented, especially in women. We conducted a pilot study to document the relationships between daily insulin dose, A1C, body composition, and lipid profile in 16 young (aged 28.1 ± 8.9 years) well-controlled (A1C 6.9 ± 0.7%) type 1 diabetic women.

BMI, waist circumference, fat mass, and fat-free mass were measured. Total, visceral, and subcutaneous adipose tissue (TAT, VAT, and SAT, respectively) were obtained by computed tomography. Lipid values were determined. Pearson's correlations were calculated for A1C and age-adjusted daily insulin dose with body composition and lipid profile.

Waist circumference was ≥88 cm in 25%. TAT, VAT, and SAT correlated with waist circumference (r = 0.81, 0.58, and 0.80; P < 0.05). Interestingly, age-adjusted daily insulin dose and A1C correlated with VAT (r = 0.65, −0.68; P < 0.01) but with no other body composition or metabolic parameters. A1C correlated with triglycerides after adjustment for adiposity (r = 0.37; P < 0.05).

Our results show that daily insulin dose and strict A1C appear to be related to deleterious body composition such as increased VAT. However, our cross-sectional study design did not allow us to demonstrate, as suggested by Kabadi et al. (2), that insulin therapy induces central fat deposition in type 1 diabetes. Another possibility is that increased abdominal adiposity causes insulin resistance, to higher insulin requirement.

Ingberg et al. (3) observed in type 1 diabetic female adolescents that abdominal adipose tissue, estimated by abdomen-to-leg ratio, was associated with poor A1C, increased insulin need, and elevated blood lipids. Our results differ from theirs perhaps due to the older age, longer diabetes duration, lower adiposity, and better A1C of our population. Additionally, VAT was measured by computed tomography, which is a far better measure of actual visceral adiposity.

We identified individuals with greater adiposity (25% of our population) who may have increased cardiovascular disease risk. Our challenge is to limit VAT accumulation without compromising A1C. Daily exercise was associated with substantial reductions in VAT and insulin resistance in women (4). Therefore, exercise should also be promoted in type 1 diabetic women.

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Kabadi UM, Vora A, Kabadi M: Hyperinsulinemia and central adiposity: influence of chronic insulin therapy in type 1 diabetes.
Diabetes Care
Ingberg CM, Sarnblad S, Palmer M, Schvarcz E, Berne C, Aman J: Body composition in adolescent girls with type 1 diabetes.
Diabet Med
Ross R, Janssen I, Dawson J, Kungl AM, Kuk JL, Wong SL, Nguyen-Duy TB, Lee S, Kilpatrick K, Hudson R: Exercise-induced reduction in obesity and insulin resistance in women: a randomized controlled trial.
Obesity Research