Early metformin therapy to delay menarche and augment height in girls with precocious pubarche

Abstract

Objective: To study the effects of early metformin treatment on menarche, height, and polycystic ovary syndrome (PCOS) markers. Low-birthweight (LBW) girls with precocious pubarche (PP) are at risk for an early menarche (<12 years), an adult stature below target level, and PCOS. Hyperinsulinemic insulin resistance is thought to be a key factor.

Design: Open-label, randomized study.

Setting: University hospital.

Patient(s): Thirty-eight LBW-PP girls.

Intervention(s): At age 8 years, girls were randomly assigned to remain untreated or to receive metformin for 4 years; subsequently, both subgroups were followed without treatment until each girl was postmenarcheal.

Main outcome measure(s): Age at menarche, height, weight, endocrine-metabolic state (fasting blood), body composition (by absorptiometry), abdominal fat (subcutaneous vs. visceral), and hepatic adiposity (by magnetic resonance imaging).

Result(s): At last assessment, girls in each subgroup were on average 2 years beyond menarche; the mean growth velocity was below 2 cm/years. Age at menarche was 11.4 ± 0.1 years in untreated girls and 12.5 ± 0.2 years in metformin-treated girls; the latter girls were taller and much leaner (with less visceral and hepatic fat) and had more favorable levels of circulating insulin, androgens, and lipids.

Conclusion(s): Early metformin therapy (age ∼ 8-12 years) suffices to delay menarche; to augment postmenarcheal height; to reduce total, visceral, and hepatic adiposity; and to curb the endocrine-metabolic course of LBW-PP girls away from adolescent PCOS.