Previous studies indicate that increased QRS duration in ECG is related to the risk of all-cause death. However, the association of QRS duration with the risk of sudden cardiac death (SCD) is not ...well documented in large population-based studies. Our aim was to examine the relation of QRS duration with SCD in a population-based sample of men.
This prospective study was based on a cohort of 2049 men aged 42 to 60 years at baseline with a 19-year follow-up, during which a total of 156 SCDs occurred. As a continuous variable, each 10-ms increase in QRS duration was associated with a 27% higher risk for SCD (relative risk, 1.27; 95% confidence interval, 1.14-1.40; P<0.001). Subjects with QRS duration of >110 ms (highest quintile) had a 2.50-fold risk for SCD (relative risk, 2.50; 95% confidence interval, 1.38-4.55; P=0.002) compared with those with QRS duration of <96 ms (lowest quintile), after adjustment for established key demographic and clinical risk factors (age, alcohol consumption, previous myocardial infarction, smoking, serum low- and high-density lipoprotein cholesterol, C-reactive protein, type 2 diabetes mellitus, body mass index, systolic blood pressure, and cardiorespiratory fitness). In addition to QRS duration, smoking, previous myocardial infarction, type 2 diabetes mellitus, cardiorespiratory fitness, body mass index, systolic blood pressure, and C-reactive protein were independently associated with the risk of SCD.
QRS duration is an independent predictor of the risk of SCD and may have utility in estimating SCD risk in the general population.
The inverse association between physical activity and arterial thrombotic disease is well established. Evidence on the association between physical activity and venous thromboembolism (VTE) is ...divergent. We conducted a systematic review and meta-analysis of published observational prospective cohort studies evaluating the associations of physical activity with VTE risk. MEDLINE, Embase, Web of Science, and manual search of relevant bibliographies were systematically searched until 26 February 2019. Extracted relative risks (RRs) with 95% confidence intervals (CIs) for the maximum versus minimal amount of physical activity groups were pooled using random effects meta-analysis. Twelve articles based on 14 unique prospective cohort studies comprising of 1,286,295 participants and 23,753 VTE events were eligible. The pooled fully-adjusted RR (95% CI) of VTE comparing the most physically active versus the least physically active groups was 0.87 (0.79–0.95). In pooled analysis of 10 studies (288,043 participants and 7069 VTE events) that reported risk estimates not adjusted for body mass index (BMI), the RR (95% CI) of VTE was 0.81 (0.70–0.93). The associations did not vary by geographical location, age, sex, BMI, and methodological quality of studies. There was no evidence of publication bias among contributing studies. Pooled observational prospective cohort studies support an association between regular physical activity and low incidence of VTE. The relationship does not appear to be mediated or confounded by BMI.
The aim of the study was to determine whether impaired fasting plasma glucose (FPG) and type 2 diabetes may be risk factors for sudden cardiac death (SCD).
This prospective study was based on 2,641 ...middle-aged men 42-60 years of age at baseline. Impaired FPG level (≥5.6 mmol/L) among nondiabetic subjects (501 men) was defined according to the established guidelines, and the group with type 2 diabetes included subjects (159 men) who were treated with oral hypoglycemic agents, insulin therapy, and/or diet.
During the 19-year follow-up, a total of 190 SCDs occurred. The relative risk (RR) for SCD was 1.51-fold (95% CI 1.07-2.14, P = 0.020) for nondiabetic men with impaired FPG and 2.86-fold (1.87-4.38, P < 0.001) for men with type 2 diabetes as compared with men with normal FPG levels, after adjustment for age, BMI, systolic blood pressure, serum LDL cholesterol, smoking, prevalent coronary heart disease (CHD), and family history of CHD. The respective RRs for out-of-hospital SCDs (157 deaths) were 1.79-fold (1.24-2.58, P = 0.001) for nondiabetic men with impaired FPG and 2.26-fold (1.34-3.77, P < 0.001) for men with type 2 diabetes. Impaired FPG and type 2 diabetes were associated with the risk of all-cause death. As a continuous variable, a 1 mmol/L increment in FPG was related to an increase of 10% in the risk of SCD (1.10 1.04-1.20, P = 0.001).
Impaired FPG and type 2 diabetes represent risk factors for SCD.
Evidence suggests that higher cardiorespiratory fitness (CRF) levels can offset the increased risk of adverse outcomes due to other risk factors. The impact of high CRF levels on the increased risk ...of chronic obstructive pulmonary disease (COPD) due to low socioeconomic status (SES) is unknown. We aimed to assess the combined effects of SES and CRF on the future risk of COPD.
We employed a prospective cohort of 2312 Finnish men aged 42–61 years at study entry. Socioeconomic status was self-reported and CRF was objectively assessed using respiratory gas exchange analyzers. Both exposures were categorized as low and high based on median cutoffs. Multivariable-adjusted hazard ratios (HRs) with confidence intervals (CIs) were estimated.
During 26.0 years median follow-up, 120 COPD cases occurred. Low SES was associated with increased COPD risk and high CRF was associated with reduced COPD risk. Compared with high SES-low CRF, low SES-low CRF was associated with an increased COPD risk 2.36 (95% CI: 1.44–3.87), with no evidence of an association for low SES-high CRF and COPD risk 1.46 (95% CI:0.82–2.60).
In middle-aged Finnish men, SES and CRF are each independently associated with COPD risk. However, high CRF levels offset the increased COPD risk related to low SES.
•Low socioeconomic status (SES) is associated with increased COPD risk.•High cardiorespiratory fitness is associated with reduced COPD risk.•High CRF levels offset the increased COPD risk related to low SES.
Chronic obstructive pulmonary disease (COPD) is characterized by chronic lung inflammation. The relationship between cardiorespiratory fitness (CRF) and COPD has not been well characterized. We aimed ...to evaluate the independent and joint associations of inflammation (high-sensitivity C-reactive protein hsCRP) and CRF with COPD risk in a cohort of White men.
Among 2274 men aged 42-61 yr at baseline, serum hsCRP level was measured using an immunometric assay and CRF was assessed using a respiratory gas exchange analyzer. The level of hsCRP was categorized as normal and high (≤3 and >3 mg/L, respectively) and CRF as low and high. We corrected for within-person variability in exposures using repeat measurements taken several years apart.
A total of 116 COPD cases occurred during a median follow-up of 26.0 yr. The age-adjusted regression dilution ratio of hsCRP and CRF was 0.57 (95% CI, 0.50-0.64) and 0.58 (95% CI, 0.53-0.64), respectively. Comparing high versus normal hsCRP levels, the multivariable-adjusted HR for COPD was 1.79 (95% CI, 1.20-2.68). The COPD risk decreased linearly with increasing CRF. The multivariable-adjusted HR for COPD per 1-SD increase in CRF was 0.75 (95% CI, 0.60-0.95). Compared with men with normal hsCRP-low CRF, high hsCRP-low CRF was associated with an increased COPD risk, 1.80 (95% CI, 1.12-2.89), with no evidence of an association for high hsCRP-high CRF and COPD risk, 1.35 (95% CI, 0.68-2.69).
Both hsCRP and CRF are associated with COPD risk in middle-aged men. However, high CRF levels attenuate the increased COPD risk related to high hsCRP levels.
Regular physical activity is well established to be associated with reduced risk of cardiovascular disease outcomes. Whether physical activity is associated with the future risk of atrial ...fibrillation (AF) remains a controversy. Using a systematic review and meta-analysis of published observational cohort studies in general populations with at least one-year of follow-up, we aimed to evaluate the association between regular physical activity and the risk of AF. Relevant studies were sought from inception until October 2020 in MEDLINE, Embase, Web of Science, and manual search of relevant articles. Extracted relative risks (RRs) with 95% confidence intervals (CIs) for the maximum versus the minimal amount of physical activity groups were pooled using random-effects meta-analysis. Quality of the evidence was assessed by GRADE. A total of 23 unique observational cohort studies comprising of 1,930,725 participants and 45,839 AF cases were eligible. The pooled multivariable-adjusted RR (95% CI) for AF comparing the most physically active versus the least physically active groups was 0.99 (0.93–1.05). This association was modified by sex: an increased risk was observed in men: 1.20 (1.02–1.42), with a decreased risk in women: 0.91 (0.84–0.99). The quality of the evidence ranged from low to moderate. Pooled observational cohort studies suggest that the absence of associations reported between regular physical activity and AF risk in previous general population studies and their aggregate analyses could be driven by a sex-specific difference in the associations – an increased risk in men and a decreased risk in women.
Systematic review registration:
PROSPERO 2020: CRD42020172814
Altered fractal heart rate (HR) dynamics occur during various disease states, but the physiological background of abnormal fractal HR behavior is not well known. We tested the hypothesis that the ...fractal organization of human HR dynamics is determined by the balance between sympathetic and vagal outflow.
A short-term fractal scaling exponent (alpha1) of HR dynamics, analyzed by the detrended fluctuation analysis (DFA) method, and the high-frequency (HF) and low-frequency (LF) spectral components of R-R intervals (0.15 to 0.4 Hz; n=13), along with muscle sympathetic nervous activity (MSNA) from the peroneus nerve (n=11), were assessed at rest and during cold face and cold hand immersion in healthy subjects. During cold face immersion, HF power increased (from 6.9+/-1.3 to 7.6+/-1.2 ln ms2, P<0.01), as did MSNA (from 32+/-17 to 44+/-14 bursts/100 heartbeats, P<0.001), and LF/HF ratio decreased (P<0.01). Cold hand immersion resulted in a similar increase in MSNA (from 34+/-17 to 52+/-19 bursts/100 heartbeats, P<0.001) but a decrease in HF spectral power (from 7.0+/-1.3 to 6.5+/-1.1 ln ms2, P<0.05) and an increase in the LF/HF ratio (P<0.05). The fractal scaling index alpha1 decreased in all subjects (from 0.85+/-0.27 to 0.67+/-0.30, P<0.0001) during cold face immersion but increased during cold hand immersion (from 0.77+/-0.22 to 0.97+/-0.20, P<0.01).
The fractal organization of human HR dynamics is determined by a delicate interplay between sympathetic and vagal outflow, with the breakdown of fractal HR behavior toward more random dynamics occurring during coactivation of sympathetic and vagal outflow.
Aims Current treatment may have changed the risk profiles of survivors of acute myocardial infarction (AMI). We evaluated the utility of Holter-based risk variables in the prediction of sudden ...cardiac death (SCD) among survivors of AMI treated with modern therapy. Methods and results A total of 2130 AMI patients (mean age 59±10 years) were included. The patients were treated with modern therapeutic strategies, for example, 94% were on β-blocking therapy and 70% underwent coronary revascularization. Various risk parameters from Holter monitoring were analysed. During a median follow-up of 1012 days (interquartile range: 750–1416 days), cardiac mortality was 113/2130, including 52 SCDs. All Holter variables predicted the occurrence of SCD (P<0.01), but only reduced post-ectopic turbulence slope (TS) (P<0.001) and non-sustained ventricular tachycardia (P<0.01) remained as marked SCD predictors after adjustment for age, diabetes, and ejection fraction (EF). In a subgroup analysis, none of the Holter variables predicted SCD among those with an EF ≤0.35, but many variables predicted SCD among those with an EF >0.35, particularly TS (hazard ratio 5.9; 95% CI 2.9–11.7, P<0.001). Conclusion Among the post-AMI patients treated according to the current guidelines, the incidence of SCD is low. Various Holter variables still predict the occurrence of SCD, particularly among the patients with preserved left ventricular function.
Though evidence suggests that higher cardiorespiratory fitness (CRF) levels can offset the adverse effects of other risk factors, it is unknown if CRF offsets the increased risk of chronic ...obstructive pulmonary disease (COPD) due to smoking. We aimed to evaluate the combined effects of smoking status and CRF on incident COPD risk using a prospective cohort of 2295 middle-aged and older Finnish men. Peak oxygen uptake, assessed with a respiratory gas exchange analyzer, was used as a measure of CRF. Smoking status was self-reported. CRF was categorised as low and high based on median cutoffs, whereas smoking status was classified into smokers and non-smokers. Multivariable-adjusted hazard ratios with confidence intervals (CIs) were calculated. During 26 years median follow-up, 119 COPD cases were recorded. Smoking increased COPD risk 10.59 (95% CI 6.64–16.88), and high CRF levels decreased COPD risk 0.43 (95% CI 0.25–0.73). Compared with non-smoker-low CRF, smoker-low CRF was associated with an increased COPD risk in multivariable analysis 9.79 (95% CI 5.61–17.08), with attenuated but persisting evidence of an association for smoker-high CRF and COPD risk 6.10 (95% CI 3.22–11.57). An additive interaction was found between smoking status and CRF (RERI = 6.99). Except for CRF and COPD risk, all associations persisted on accounting for mortality as a competing risk event. Despite a wealth of evidence on the ability of high CRF to offset the adverse effects of other risk factors, it appears high CRF levels have only modest attenuating effects on the very strong association between smoking and COPD risk.
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