Impact of Cardiorespiratory Fitness on Survival in Men with Low Socioeconomic Status

Aims Although both low socioeconomic status (SES) and poor cardiorespiratory fitness (CRF) are associated with increased chronic disease and heightened mortality, it remains unclear whether moderate-to-high levels of CRF are associated with survival benefits in low SES populations. This study evaluated the hypothesis that SES and CRF predict all-cause mortality and cardiovascular disease mortality and that moderate-to-high levels of CRF may attenuate the association between low SES and increased mortality. Methods This study included 2368 men, who were followed in the Kuopio Ischaemic Heart Disease Study cohort. CRF was directly measured by peak oxygen uptake during progressive exercise testing. SES was characterized using self-reported questionnaires. Results During a 25-year median follow-up, 1116 all-cause mortality and 512 cardiovascular disease mortality events occurred. After adjusting for potential confounders, men with low SES were at increased risks for all-cause mortality (hazard ratio 1.49, 95% confidence interval: 1.30–1.71) and cardiovascular disease mortality (hazard ratio1.38, 1.13–1.69). Higher levels of CRF were associated with lower risks of all-cause mortality (hazard ratio 0.54, 0.45–0.64) and cardiovascular disease mortality (hazard ratio 0.53, 0.40–0.69). In joint associations of SES and CRF with mortality, low SES-unfit had significantly higher risks of all-cause mortality (hazard ratio 2.15, 1.78–2.59) and cardiovascular disease mortality (hazard ratio 1.95, 1.48-2.57), but low SES-fit was not associated with a heightened risk of cardiovascular disease mortality (hazard ratio 1.09, 0.80-1.48) as compared with their high SES-fit counterparts. Conclusion Both SES and CRF were independently associated with subsequent mortality; however, moderate-to-high levels of CRF were not associated with an excess risk of cardiovascular disease mortality in men with low SES.peerReviewe

Normal Heart Rate with Tilt, Yet Autonomic Dysfunction in Persons with Down Syndrome

Persons with Down syndrome (DS) exhibit altered autonomic function at rest and in response to adrenergic stimuli. It is unknown whether a subset of persons with DS that have similar HR responses to a task would have similar responses in HR variability (HRV). Purpose: This study aimed to compare cardiac autonomic function during upright tilt using HRV analysis in persons with and without DS when persons with and without DS were matched for the change in HR. Methods: Persons with (25 T 2 yr; 30.4 T 1.9 kgImj2 , n = 15) and without DS (27 T 2 yr; 24.7 T 1.1 kgImj2 , n = 15) were matched on their HR response to a 5-min tilt at 80-, whereas a subset of persons with DS (28 T 3 yr; 33.5 T 2.0 kgImj2 , n = 11) were not matched for the change in HR. HRV was assessed in both the frequency (natural log transformation (Ln) of low frequency (LF), high frequency (HF), LF/HF ratio, and total power (TP)) and time domains (root mean square of successive differences [RMSSD]). Results: Changes in HR were similar in DS-matched and control but lower in DS-not matched. Tilt effects were observed for LnHF, LNTP, and RMSSD in all groups (P G 0.05). Both groups of persons with DS exhibited reduction in LnLF, with no change in the control group (P G 0.05). The increase in LF/HF was greater in the group without DS when compared with that in DS-not matched (8.71 T 2.38 vs 2.34 T 1.39, P G 0.05) but not when compared with that in DS-matched (3.59 T 1.10, P = 0.075). Conclusions: Despite similar HR response to passive upright tilt in the DS-matched, we still observed reduced sympathetic dominance in response to upright tilt in persons with D

Associations of Cardiorespiratory Fitness With Estimated Remnant Cholesterol and Non–High-Density Lipoprotein Cholesterol in Healthy Men

Remnant cholesterol (RC) and non–high-density lipoprotein cholesterol (non–HDL-C) may contribute to the residual risk for atherosclerotic cardiovascular disease. High cardiorespiratory fitness (CRF) is associated with favorable traditional lipid profiles, but its relation with RC and non–HDL-C remains unclear. We analyzed cross-sectional data on 4,613 healthy men (mean age 49 years). CRF was measured using peak oxygen uptake during incremental exercise testing and categorized into quartiles. RC was estimated as total cholesterol minus HDL-C and low-density lipoprotein cholesterol, and elevated RC was defined as ≥38 mg/100 ml (90 percentile). Non–HDL-C was calculated as total cholesterol minus HDL-C, and high non–HLD-C was defined as ≥190 mg/100 ml. CRF was inversely associated with RC (β −0.31, 95% confidence interval [CI] −0.39 to −0.24) and non–HDL-C (β −0.34, 95% CI −0.57 to −0.11) after adjustment for several risk factors. Each metabolic equivalent increment in CRF was associated with lower odds of having elevated RC (odds ratio [OR] 0.85, 95% CI 0.77 to 0.93) and non–HDL-C (OR 0.93, 95% CI 0.85 to 1.00) in multivariable analysis. Compared with the bottom quartile, the top quartile of CRF had significantly lower odds of elevated RC (OR 0.63, 95% CI 0.45 to 0.88) and non–HDL-C (OR 0.68, 95% CI 0.51 to 0.91). In conclusion, higher CRF was independently associated with lower levels of RC and non–HDL-C and lower odds of the prevalence of elevated RC and non–HDL-C in healthy men