Adipocyte size and number have been suggested to predict the development of metabolic complications in obesity. However, the genetic and environmental determinants behind this phenomenon remain unclear.
We studied this question in rare-weight discordant (intra-pair difference (?) body mass index (BMI) 3-10 kg m(-2), n=15) and concordant (?BMI 0-2 kg m(-)(2), n=5) young adult (22-35 years) monozygotic twin pairs identified from 10 birth cohorts of Finnish twins (n=5 500 pairs). Subcutaneous abdominal adipocyte size from surgical biopsies was measured under a light microscope. Adipocyte number was calculated from cell size and total body fat (D ? A).
The concordant pairs were remarkably similar for adipocyte size and number (intra-class correlations 0.91-0.92, P