Risk of developing diabetes and cardiovascular disease in metabolically unhealthy normal-weight and metabolically healthy obese individuals

Abstract

Context: The risk of cardiovascular disease (CVD) and type 2 diabetes mellitus (DM) associated with obesity appears to be influenced by the coexistence of other metabolic abnormalities.

Objective: We examined the risk of developing CVD and DM in metabolically healthy obese (MHO) and metabolically unhealthy normal weight (MUH-NW) individuals.

Design and setting: We analyzed prospective data of the San Antonio Heart Study, a population-based study among Mexican Americans and non-Hispanic whites (median follow-up, 7.4 y).

Participants: Incident DM and CVD were assessed in 2814 and 3700 participants aged 25 to 64 years, respectively.

Main measures: MHO was defined as obesity (body mass index ≥ 30 kg/m(2)) with no more than one metabolic abnormality, and MUH-NW was defined as body mass index <25 kg/m(2) with two or more abnormalities.

Results: In logistic regression models, BMI was associated with incident DM after controlling for demographics, family history of DM, and fasting glucose (odds ratio × 1 SD, 1.7 [95% CI, 1.5-2.0]). Both MUH-NW and MHO individuals had an increased DM risk (2.5 [1.1-5.6] and 3.9 [2.0-7.4], respectively). Similarly, BMI was related to incident CVD after adjusting for demographics and Framingham risk score (1.3 [1.1-1.6]). Incident CVD was also increased in MUH-NW and MHO individuals (2.9 [1.3-6.4] and 3.9 [1.9-7.8], respectively). Results were consistent across gender and ethnic categories.

Conclusion: The risk of developing DM and CVD is increased in MUH-NW and MHO individuals. Screening for obesity and other metabolic abnormalities should be routinely performed in clinical practice to institute appropriate preventive measures.

Figure 1.

CVD-free survival curves in normal-weight and obese individuals with normal and abnormal metabolic status. MHO (solid curve), MUH-NW (dashed curve), and metabolically unhealthy obese (dotted curve) individuals had a higher risk of developing CVD than metabolically healthy normal-weight individuals (long-dashed curve) (log rank test, P < .001 for all three comparisons). CVD risk in MUH-NW individuals did not differ from that in MHO (P = .225) and metabolically unhealthy obese individuals (P = .939).