Diabetes Reduces Growth and Body Composition More in Male Than in Female Rats

Abstract

Food restriction and/or starvation has a consistently greater and more permanent effect on physical growth in males than in females. Because diabetes may be viewed as being analogous to starvation, we tested the hypothesis that diabetes would reduce growth more in male than in female rats. Diabetes was induced with streptozotocin (65–125 mg/kg IP) at 3 weeks of age in 7 female and 10 male Lewis rats. Body weight (BW) and blood glucose (bGlc) were measured over the following 8 weeks. Subsequently, animals were assessed for body (ano-nasal; ANL) and bone length (tibia; TBL) and chemically analyzed for body composition. Results were compared to age-matched controls (male = 11; female = 9). A 2-way factorial analysis of covariance (ANCOVA), with body weight as the covariate, was used to test for statistical significance for the effects of gender and diabetes on body composition (fat and protein mass) and linear growth because control males and females had significantly different body weights. There were no significant differences in bGlc between genders. However, males had a greater decrease from controls in BW (−45% vs. −13%), protein (−48% vs. −11%), fat (−89% vs. −65%), TBL (−13% vs. −0%), and ANL (−17% vs. −5%) compared to females. In addition, males had a greater absolute decrease from controls in protein (−40 g vs. −5 g) and fat (−39 g vs. − 23 g) mass. These results suggest that male rats are more susceptible than females to the deleterious effects of diabetes on linear growth and body composition.