Birth weight was associated positively with gluteofemoral fat mass and inversely with 2-h postglucose insulin concentrations, a marker of insulin resistance, in young normal-weight Japanese women.

Introduction: We tested whether birth weight might be associated with gluteofemoral fat mass and insulin sensitivity later in life. Materials and methods: Body size trajectory since birth, body composition at age 20, and markers of insulin resistance were measured in 316 Japanese women. A subset of 148 women underwent a 75 g oral glucose tolerance test. Multiple linear regression analyses were used to identify most important determinants of birth weight.
Results: Birth weight was correlated positively with height and weight at age 12, 15, and 20 years (all p < 0.001 except for weight at 12 years, p = 0.03). Although it showed no correlation with BMI at age 12 and 15, it was correlated positively with current BMI (p = 0.006). It showed positive correlations with lean mass in arms, legs, trunk, and the whole body at age 20 (all p < 0.001). Additionally, it was correlated positively with leg (gluteofemoral) fat mass (p = 0.007), although there was no correlation with total body and trunk fat mass. Furthermore, weight at birth showed inverse correlations with 2-h postglucose insulin concentrations (p = 0.008) whereas it was not correlated with fasting insulin and homeostasis model assessment-insulin resistance. In a multiple regression analysis, which included anthropometric and biochemical variables as independent variables, appendicular muscle mass (standardized β 0.394, p < 0.001) emerged as a single determinant of birth weight (R 2 = 0.15). In a model which included gluteofemoral fat mass and 2-h postglucose insulin, birth weight was associated with gluteofemoral fat mass (standardized β 0.240, p = 0.003) and 2-h postglucose insulin concentrations (standardized β - 0.217, p = 0.007) (R 2 = 0.09). Conclusions: Birth weight was associated positively with gluteofemoral fat mass and inversely with 2-h postglucose insulin concentrations, a marker of insulin resistance. © The Japan Diabetes Society 2021.