Abdominal obesity phenotypes and incident diabetes over 12 years of follow-up: The Tehran Lipid and glucose study.

AIMS: To investigate future diabetes in different abdominal obesity phenotypes during 12 years of follow-up.

METHODS: For this population-based cohort, 7982 adults without diabetes including 3533 men and 4449 women, aged ≥20 years were selected from the Tehran Lipid and Glucose Study. Abdominal obesity was defined according to the national cutoffs for waist circumference (WC). Metabolic health was defined as having ≤1 metabolic abnormality based on Joint Interim Statement (JIS) criteria other than WC. Participants were classified into 4 groups of abdominal obesity phenotypes: Metabolically healthy non-abdominal obese (MHNAO), metabolically healthy abdominal obese (MHAO), metabolically unhealthy non-abdominal Obese (MUNAO), and metabolically unhealthy abdominal obese (MUAO).

RESULTS: In total, 1018 cases of incident diabetes occurred. Compared to the MHNAO phenotype, based on multivariate Cox regression models, diabetes risk was increased in all unhealthy phenotypes except the MUNAO phenotype in men. Regarding the association of the MHAO phenotype with incident diabetes, borderline statistical significance in men [HR 1.5 (95% CI: 1.0-2.36), p-value: 0.07] and statistical significance in women [HR 1.68 (95% CI: 1.08-2.6)] were detected.

CONCLUSIONS: In addition to unhealthy phenotypes except the MUNAO phenotype in men, the MHAO phenotype is also associated with incident diabetes, highlighting the importance of preventive strategies in this subgroup of abdominally obese subjects.