Meta-analysis finds BMI, but not waist circumference, associated with prediabetes risk

This meta-analysis synthesized evidence from 28 cohort studies, retrieved from 8,434 records, to examine the association between anthropometric measures of obesity and the risk of developing prediabetes. The analysis focused on body mass index (BMI) and waist circumference (WC) as exposures, with the primary outcome being the development of prediabetes during longitudinal follow-up. The specific populations, settings, and follow-up durations of the included studies were not reported.

The main results showed a significant positive association between BMI and prediabetes risk. When analyzed as a continuous variable, the pooled risk ratio (RR) was 1.10 (95% CI: 1.03, 1.17). For categorical BMI, the RR was 1.52 (95% CI: 1.19, 1.94). A linear dose-response relationship was observed, indicating a 4.6% increase in prediabetes risk for every 1-unit increase in BMI. In contrast, analyses for waist circumference, both as a continuous and categorical variable, found no significant association with prediabetes risk.

Safety and tolerability data were not reported. Key limitations include substantial statistical heterogeneity among the included studies and limited data available for the waist circumference analyses, which weakens the certainty of the null finding for WC. The funding sources and potential conflicts of interest were also not reported.

In practice, these findings support the use of BMI as a risk marker for prediabetes in clinical assessment, underscoring the value of monitoring general obesity for early risk stratification. However, clinicians should interpret these results cautiously as they demonstrate an association, not causation, and prediabetes itself is a surrogate outcome. The lack of a significant finding for waist circumference should not be overgeneralized due to data limitations.