The study examined the association between resting heart rate and risk of type 2 diabetes (T2D) and cardiovascular events in an Inner Mongolian population.

Based on a cross-sectional survey carried out in 2003, 2530 participants were reinvestigated between 2013 and 2014. All participants were classified into four groups (quartiles) according to heart rate. Primary outcomes were hypertension, T2D, major macrovascular events and all-cause deaths. Logistic regression models were used to estimate odds ratios (ORs), and shape-restricted cubic spline regressions were conducted to investigate the associations between resting heart rate and study outcomes.

During the 10-year follow-up, 502 (41.6%) patients developed hypertension, 200 (10.4%) had diabetes, 464 (18.3%) experienced major macro-vascular events and 306 (14.3%) died. Resting heart rate was significantly associated with an increased risk of hypertension, T2D, major macro-vascular events and all-cause deaths: adjusted ORs (95% CI) for the highest vs lowest quartiles of heart rate were 1.51 (1.06–2.15), 2.44 (1.54–3.85), 1.55 (1.14–2.10) and 1.57 (1.05–2.34), respectively. Multivariable-adjusted restricted cubic spline regression models showed a linear association between heart rate and the four outcomes (all P < 0.05 for linearity). The addition of heart rate to basic risk factors improved the prediction of risk of diabetes and all-cause deaths [indices of continuous net reclassification improvement and of integrated discrimination improvement were 21.92% (P = 0.002) and 22.69% (P < 0.001), and 0.72% (P = 0.01) and 0.58% (P = 0.03), respectively].

Higher heart rates were associated with an increased risk of hypertension, T2D, major macro-vascular events and all-cause deaths among Inner Mongolians, suggesting that heart rate measurement may be of value as a potential clinical and diagnostic marker.