Adipose morphology and metabolic disease

Adipose morphology is defined as the number and size distribution of adipocytes (fat cells) within adipose tissue. Adipose tissue with fewer, but larger adipocytes is termed as having a ‘hypertrophic’ morphology, whereas adipose with many adipocytes, of a smaller size, is termed a ‘hyperplastic’ morphology. Hypertrophic adipose morphology is positively associated with insulin resistance, diabetes and cardiovascular disease. Contrastingly, hyperplastic morphology is associated with improved metabolic parameters. These phenotypic associations suggest that adipose morphology influences risk for cardiometabolic disease. Intriguingly, monozygotic twin studies have determined that adipose morphology is in part genetically determined. Therefore, identifying the genetic regulation of adipose morphology may help predict, prevent and ameliorate insulin resistance and associated metabolic diseases. Here we review the current literature regarding adipose morphology in relation to; (i) metabolic and medical implications, (ii) methods used to assess adipose morphology, and (iii) transcriptional differences between morphologies.
We further highlight three mechanisms hypothesized to promote adipocyte hypertrophy and thus regulate adipose morphology.