Effect of Puberty on Markers of Glomerular Hypertrophy and Hypertension in IDDM

Margaret L Lawson; Etienne B Sochett; Peter G Chait; J Williamson Balfe; Denis Daneman

doi:10.2337/diab.45.1.51

Original Articles

Effect of Puberty on Markers of Glomerular Hypertrophy and Hypertension in IDDM

Margaret L Lawson,
Etienne B Sochett,
Peter G Chait,
J Williamson Balfe and
Denis Daneman

Department of Pediatrics, Divisions of Endocrinology and Nephrology Toronto, Ontario, Canada
Department of Diagnostic Imaging, The Hospital for Sick Children and University of Toronto Toronto, Ontario, Canada

Address correspondence and reprint requests to Etienne B. Sochett, MB, FRCP(C), The Hospital for Sick Children, 555 University Ave., Toronto, Ontario M5G 1X8, Canada

Diabetes 1996 Jan; 45(1): 51-55. https://doi.org/10.2337/diab.45.1.51

Abstract

Epidemiological data implicate puberty as a factor in the initiation of diabetic nephropathy. However, the mechanism remains unclear. We hypothesized that puberty would result in an increase in glomerular hypertrophy and hypertension; these two early concomitant events are seen as pivotal to the pathophysiology of diabetic nephropathy. We studied the effect of pubertal duration on three surrogate markers of glomerular hypertrophy/hypertension: kidney volume (KV), microalbuminuria (MA), and Na-Li countertransport (CT). We recruited 177 subjects (87 female and 90 male; aged 6.2–22.1 years) with IDDM of 5 to 10 years' duration (6.8 ± 1.6 years) into three groups with different pubertal duration: prepubertal since IDDM diagnosis; prepubertal at diagnosis, now pubertal; or early puberty at diagnosis, now postpubertal. KV was measured by ultrasound and corrected for body surface area; MA was defined as urinary albumin excretion of 15–200 μg/min in two of three 24-h samples, and Na-Li CT was measured in erythrocytes. As pubertal duration increased, there was a disproportionate increase in mean KV (prepubertal, 247 ± 6 [SE] ml/1.73 m²; pubertal, 282 ± 7/1.73 m²; postpubertal, 295 ± 7/1.73 m² P = 0.001), prevalence of nephromegaly (KV > 300 ml/1.73 m²) (14, 31, and 45%, respectively, P = 0.001), and prevalence of MA (0, 9.7, and 20.5%, respectively, P = 0.003). Subjects with KV > 300 ml/1.73 m² were eight times more likely to have MA than those with KV <300 (odds ratio 8.1, 95% confidence interval 2.4–27.4, P = 0.0001). There was no effect of pubertal duration on Na-Li CT. Multiple regression with KV as the dependent variable found an association with pubertal duration, MA, Na-Li CT, and current HbA_1c (P < 0.0001). Our findings indicate that pubertal duration is an important determinant of both KV and MA and suggest that nephromegaly precedes microalbuminuria. We postulate that these effects are attributable to the influence of the pubertal milieu on glomerular hypertrophy/hypertension.