Insulin resistance in young adults born small for gestational age (SGA)

Objective: This work aimed to assess glucose metabolism and insulin sensitivity in young adults born small for gestational age (SGA) as well as to measure the body composition and adipocytokines of these subjects. Methods: A total of 108 out of 342 SGA-born participants were invited for reexamination from the former Bavarian Longitudinal Study (BLS), in which 7505 risk-newborns of the years 1985 to 1986 were prospectively followed. Of these, 76 (34 female/42 male) participants at the age of 19.7 +/- 0.5 years were enrolled. Clinical examination and oral glucose tolerance testing (oGTT) was performed with assessment of insulin resistance indices, HbA1c, body mass index (BMI), adipocytokines, and body composition by bioimpedance analysis (BIA). Results: A total of 25 out of 76 (32.9%) patients had abnormal fasting and/or glucose-stimulated insulin levels. Glucose values measured during oGTT showed no abnormalities, except one participant who had impaired glucose tolerance. Homeostasis model assessment insulin resistance index (HOMA-IR) was 1.92 +/- 4.2, and insulin sensitivity index by Matsuda (ISIMatsuda) showed mean values of 7.85 +/- 4.49. HOMA-IR > 2.5 was found in 8 patients (10.5%), and 20 patients (26.3%) had an ISIMatsuda < 5, both interpreted as insulin resistant. No alterations of adipocytokines were found. Fat mass (FM) measured by BIA was within the normal range for both genders and correlated significantly with BMI (r = 0.465, p < 0.001) and leptin (r = 0.668, p < 0.001), but not with adiponectin. Insulin resistance correlated with change in weight-for-height Z-score during the first 3 months of age, indicating that weight gain during that early phase might be a risk factor for the development of insulin resistance in children born SGA. Conclusions: A high percentage of insulin-resistant subjects were reconfirmed in a large German cohort of young adults born SGA. Therefore, regular screening for disturbances in glucose metabolism is recommended in these subjects.