An inverse dose-dependent association exists between cardiorespiratory fitness and type 2 diabetes (T2D) risk, according to the results of a meta-analysis published in Obesity. Higher levels of cardiorespiratory fitness may also eliminate the diabetogenic effect of statins use.
Evidence has shown that physical activity is a modifying protective factor against the onset of T2D. Cardiorespiratory fitness is shown to hold potential superiority over physical activity in assessing risk for cardiovascular disease. For this reason, researchers conducted a meta-analysis to quantify the association of cardiorespiratory fitness with risk for T2D in the general population, as well as in statin users, and to elucidate the effects of cardiorespiratory fitness and adiposity on T2D risk.
The researchers performed a systematic search of PubMed, Cochrane Library, and Web of Science through May 2018 for studies relating to “cardiorespiratory fitness” and “diabetes.” The studies selected were published in English and had cohort designs, reported the association of cardiorespiratory fitness and risk for T2D as the major outcome, determined cardiorespiratory fitness using an exercise stress test, and provided hazard ratios (HRs) with 95% CIs.
In total, 15 studies were included in the analysis. The pooled HRs for T2D for every 1 metabolic equivalent increase in cardiorespiratory fitness were 0.90 (95% CI, 0.86-0.94) for the general population and 0.92 (95% CI, 0.87-0.97) for statin users, and the HRs were linearly shaped (both P >.40). Compared with statin nonusers, there was an increased risk for T2D in statin users with low or moderate cardiorespiratory fitness. This increased risk was not reported in patients with high cardiorespiratory fitness.
Of note, the HR for T2D between fit overweight/obese patients vs fit normal-weight patients was larger than that of unfit normal-weight patients vs fit normal-weight patients (HR, 2.05 vs 1.26; P =.004).
On the basis of their results, “weight control may play a more important role than [cardiorespiratory fitness] improvement in preventing [T2D],” wrote the researchers. “However, it is worth noting that modest weight loss might be not sufficient to reduce the morbidities or mortalities related to cardiovascular events, and improving [cardiorespiratory fitness] might be more important than promoting weight loss with regard to reducing all-cause or cardiovascular disease mortality risk.”
Qiu S, Cai X, Yang B, et al. Association between cardiorespiratory fitness and risk of type 2 diabetes: a meta-analysis. Obesity. 2019;27(2):315-324.