Association between type 2 diabetes and non-exercise estimated cardiorespiratory fitness among adults: evidences from a middle-income country

Abstract

Objective: The objective of this study is to assess the association between type 2 diabetes (T2D) and cardiorespiratory fitness (CRF) estimated through a non-exercise model in a large representative group of Brazilian adults.

Study design: The study design of this study is a cross-sectional population-based study.

Methods: The presence of T2D was assessed through self-report in 42,631 individuals aged 20-59 years. The CRF was predicted from a non-exercise equation containing the following data: sex, age, body mass index, and physical activity level. The corresponding metabolic equivalent (MET) value was used to classify participants into the following four groups based on the cutpoints: <6, 6-9, 10-11, and ≥12 METs. Crude and multivariable-adjusted logistic regressions were carried out to determine the association between CRF and the presence of diabetes.

Results: Significant linear trends were observed in diabetes across different categories of CRF in men. In women, however, linear trends were not observed in T2D across '10-11' and '≥12' categories. A 1-MET increase in estimated CRF was associated with 29% lower odds of diabetes in men and 14% in women after adjusting all the potential confounders (P < 0.001).

Conclusions: The presence of T2D was inversely associated with every CRF level in men and with 6-9 METs when comparing with <6 METs in women, through a non-exercise model in Brazilian adults. This finding suggests that a practical, viable, and low-cost measurement of CRF could be applied in lower income countries to assess the relationship between CRF and T2D. However, new non-exercise models are needed to better detect T2D in women.

Keywords: Diabetes; Epidemiology; Exercise capacity; Fitness; Regression.