Cardiorespiratory fitness, body mass index and mortality: a systematic review and meta-analysis

Weeldreyer NR, De Guzman JC, Paterson C, et al.

British Journal of Sports Medicine  Published Online First: 13 November 2024. 

Sudden cardiac arrest (SCA) during sports can be the first symptom of yet

Objective The purpose of this review was to assess the joint relationship of cardiorespiratory fitness (CRF) and Body Mass Index (BMI) on both cardiovascular disease (CVD) and all-cause mortality risk.

Design A systematic review and meta-analysis was conducted. Pooled HR and 95% CI were calculated using a three-level restricted maximum likelihood estimation random-effects model with robust variance estimation. The reference group was normal weight-fit and was compared with normal weight-unfit, overweight-unfit and fit, and obese-unfit and fit.

Data sources Electronic databases (PubMed/MEDLINE, Web of Science and SportDiscus) were searched following registration on PROSPERO.

Eligibility criteria Articles meeting the following criteria were included: (1) published between January 1980 and February 2023, (2) prospective cohort study, (3) CRF assessed using a maximal or VO2peak exercise test, (4) BMI reported and directly measured, (5) joint impact of CRF and BMI on all-cause mortality or CVD mortality were analysed, and (6) the reference group was normal weight, fit individuals.

Results 20 articles were included in the analysis resulting in a total of 398 716 observations. Compared with the reference group, overweight-fit (CVD HR (95% CI): 1.50 (0.82–2.76), all-cause HR: 0.96 (0.61–1.50)) and obese-fit (CVD: 1.62 (0.87–3.01), all-cause: 1.11 (0.88–1.40)) did not have a statistically different risk of mortality. Normal weight-unfit (CVD: 2.04 (1.32–3.14), all-cause: 1.92 (1.43–2.57)), overweight-unfit (CVD: 2.58 (1.48–4.52), all-cause: 1.82 (1.47–2.24)) and obese-unfit (CVD: 3.35 (1.17–9.61), all-cause: 2.04 (1.54–2.71)) demonstrated 2–3-fold greater mortality risks.

Conclusions CRF is a strong predictor of CVD and all-cause mortality and attenuates risks associated with overweight and obesity. These data have implications for public health and risk mitigation strategies.