Urine cotinine versus self-reported smoking and the risk of chronic kidney disease.

BACKGROUND AND HYPOTHESIS: Evidence on the role of smoking in the development of chronic kidney disease (CKD) has mostly relied on self-reported smoking status. We aimed to compare the associations of smoking status as assessed by self-reports and urine cotinine with CKD risk. METHODS: Using the PREVEND prospective study, smoking status was assessed at baseline using self-reports and urine cotinine in 4333 participants (mean age, 52 years) without a history of CKD at baseline. Participants were classified as never, former, light current and heavy current smokers according to self-reports and comparable cut-offs for urine cotinine. Hazard ratios (HRs) with 95% CIs were estimated for CKD. RESULTS: The percentages of self-reported and cotinine-assessed current smokers were 27.5% and 24.0%, respectively. During a median follow-up of 7.0 years, 593 cases of CKD were recorded. In analyses adjusted for established risk factors, the HRs (95% CI) of CKD for self-reported former, light current, and heavy current smokers compared with never smokers were 1.17 (0.95-1.44), 1.48 (1.10-2.00), and 1.48 (1.14-1.93), respectively. On further adjustment for urinary albumin excretion (UAE), the HRs (95% CI) were 1.07 (0.87-1.32), 1.26 (0.93-1.70), and 1.20 (0.93-1.57), respectively. For urine cotinine-assessed smoking status, the corresponding HRs (95% CI) were 0.81 (0.52-1.25), 1.17 (0.92-1.49), and 1.32 (1.02-1.71), respectively, in analyses adjusted for established risk factors plus UAE. CONCLUSION: Self-reported current smoking is associated with increased CKD risk, but dependent on UAE. The association between urine cotinine-assessed current smoking and increased CKD risk is independent of UAE. Urine cotinine-assessed smoking status may be a more reliable risk indicator for CKD incidence than self-reported smoking status.

Physical activity and risk of atrial fibrillation in the general population: meta-analysis of 23 cohort studies involving about 2 million participants.

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.

Leisure-time cross-country skiing is associated with lower incidence of type 2 diabetes: A prospective cohort study.

BACKGROUND: Cross-country skiing is associated with reduction in risk of adverse vascular outcomes, but its association with type 2 diabetes is uncertain. We aimed to assess the associations between leisure-time cross-country skiing habits and incident type 2 diabetes. METHODS: We analysed the data of 2483 middle-aged men with no history of diabetes at baseline in the Kuopio Ischemic Heart Disease prospective study. The frequency, average duration, and intensity of leisure cross-country skiing were assessed at baseline using a 12-month physical activity questionnaire. Hazard ratios (HRs) (95% CIs) for type 2 diabetes were estimated. RESULTS: During a median follow-up of 21.6 years, 539 men developed type 2 diabetes. Type 2 diabetes risk decreased with increasing total volume of cross-country skiing up to 1,215 metabolic equivalent task (MET) hours/year. In analyses adjusted for several established risk factors, when compared with men with no cross-country skiing activity, the HRs (95% CIs) for type 2 diabetes were 0.75 (0.62-0.92) and 0.59 (0.46-0.76) for men who did 1-200 and >200 MET hours/year of cross-country skiing, respectively. Compared with men with no cross-country skiing activity, the corresponding adjusted HRs (95% CIs) for type 2 diabetes were 0.73 (0.60-0.89) and 0.64 (0.50-0.82) for men who did 1-60 and >60 minutes/week of cross-country skiing, respectively. The associations remained consistent following further adjustment for prevalent comorbidities. CONCLUSION: Total volume and duration of leisure-time cross-country skiing are each inversely and independently associated with future type 2 diabetes risk in a male population. Cross-country skiing undertaken as a leisure activity has the potential to promote public health.

Physical activity and risk of venous thromboembolism: systematic review and meta-analysis of prospective cohort studies.

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.

Self-reported smoking, urine cotinine, and risk of type 2 diabetes: Findings from the PREVEND prospective cohort study.

BACKGROUND: Smoking is a major risk factor for type 2 diabetes (T2D), but the evidence has mostly relied on self-reports. We aimed to compare the associations of smoking exposure as assessed by self-reports and urine cotinine with T2D. METHODS: Using the PREVEND prospective study, smoking status was assessed at baseline by self-reports and urine cotinine in 4708 participants (mean age, 53 years) without a history of diabetes. Participants were classified as never, former, light current and heavy current smokers according to self-reports and analogous cut-offs for urine cotinine. Hazard ratios (HRs) with 95% CIs were estimated for T2D. RESULTS: During a median follow-up of 7.3 years, 259 participants developed T2D. Compared with self-reported never smokers, the multivariable adjusted HRs (95% CI) of T2D for former, light current, and heavy current smokers were 1.02 (0.75-1.4), 1.41 (0.89-2.22), and 1.30 (0.88-1.93), respectively. The corresponding adjusted HRs (95% CI) were 0.84 (0.43-1.67), 1.61 (1.12-2.31), and 1.58 (1.08-2.32), respectively, as assessed by urine cotinine. Urine cotinine-assessed but not self-reported smoking status improved T2D risk prediction beyond established risk factors. CONCLUSION: Urine cotinine assessed smoking status may be a stronger risk indicator and predictor of T2D compared to self-reported smoking status.

Circulating Serum Copper Is Associated with Atherosclerotic Cardiovascular Disease, but Not Venous Thromboembolism: A Prospective Cohort Study.

BACKGROUND AND OBJECTIVE: Serum copper has been linked to the risk of atherosclerotic cardiovascular disease (CVD). However, the potential association between serum copper and venous thromboembolism (VTE) is not known. The principal aim was to evaluate the potential prospective association between serum copper and VTE risk. A secondary aim was to confirm or refute previously reported associations between serum copper and atherosclerotic CVD. METHODS: Serum copper was measured at baseline using atomic absorption spectrometry in 2,492 men aged 42-61 years without a history of VTE in the Kuopio Ischemic Heart Disease prospective cohort study. Cox regression models were used to calculate hazard ratios (HRs) with 95% confidence interval (CI) for VTE. RESULTS: During a median follow-up of 27.0 years, 166 VTE events occurred. The risk of VTE per 1 standard deviation increase in serum copper in age-adjusted analysis was HR: 1.02; 95% CI: 0.88-1.20, which was attenuated to HR: 0.99; 95% CI: 0.82-1.19, following further adjustment for several established and emerging risk factors. Comparing the top versus bottom tertiles of serum copper, the corresponding adjusted HRs were 1.16 (95% CI: 0.80-1.66) and 1.11 (95% CI: 0.74-1.68), respectively. In 1,901 men without a history of coronary heart disease (CHD), the multivariable-adjusted HR for CHD was 1.32 (95% CI: 1.10-1.59) comparing extreme tertiles of serum copper. CONCLUSION: In middle-aged Finnish men, we confirmed previously reported associations between high serum copper levels and increased risk of atherosclerotic CVD, but serum copper was not associated with future VTE risk. Other large-scale prospective studies conducted in women, other age-groups, and other populations are needed to confirm or refute these findings.