Sauna bathing and mortality risk: unraveling the interaction with systolic blood pressure in a cohort of Finnish men

Objectives: This cohort study aimed to investigate the potential interplay between systolic blood pressure (SBP), frequency of sauna bathing (FSB), and all-cause mortality risk among Caucasian men. Design: A prospective study was conducted, involving 2575 men aged 42 to 61 years. Baseline assessments included resting blood pressure measurements and self-reported sauna bathing habits. SBP levels were categorized as normal (Results: Over a median follow-up of 27.8 years, 1,618 deaths were recorded. In the adjusted analysis, individuals with high SBP versus low SBP showed a 29% increased all-cause mortality risk (HR 1.29, 95% CI 1.16–1.43). Similarly, those with low FSB versus high FSB exhibited a 16% elevated mortality risk (HR 1.16, 95% CI 1.02–1.31). When considering combined effects, participants with high SBP-low FSB had a 47% higher mortality risk (HR 1.47, 95% CI 1.24–1.74) compared to those with normal SBP-high FSB. However, no significant association was observed between individuals with high SBP-high FSB and mortality risk (HR 1.24, 95% CI 0.98–1.57). There were potential additive and multiplicative interactions between SBP and sauna bathing concerning mortality risk. Conclusions: This study reveals a potential interplay between SBP, sauna bathing, and mortality risk in Finnish men. Frequent sauna bathing may mitigate the increased mortality risk associated with elevated SBP.</p

Serum carotenoid tertiles by 7-year IMT_mean change (adjusted for age, examination year, ultrasound sonographer, BMI, SBP, IMT_mean, smoking, serum LDL cholesterol, physical activity, CHD in family, antihypertensive medication and serum hs-CRP.

<p>Probability values are for trend. Carotenoid tertiles (µmol/L): lycopene: ≤0.09, 0.10–0.19, ≥0.20; α-carotene: ≤0.07, 0.08–0.11, ≥0.12; β-carotene: ≤0.26, 0.27–0.41, ≥0.42.</p

Baseline characteristics of the men: the Kuopio Ischaemic Heart Disease Risk Factor (KIHD) study.

<p>Abbreviations: BMI = body mass index; CCA-IMT = intima-media thickness of the common carotid artery wall; CHD = coronary heart disease; DBP = diastolic blood pressure; hs-CRP = high sensitivity C-reactive protein; HDL = high-density lipoprotein; LDL = low-density lipoprotein; SBP = systolic blood pressure.</p>a<p>Values are given mean (SD) and percentages.</p>b<p>p for differences between smokers and non-smokers (one-way ANOVA).</p>c<p>Pack-year denote the lifelong exposure to smoking, estimated as the product of years smoked and the number of tobacco products smoked daily at the time of examination.</p

Spearman's correlation coefficients among serum levels of carotenoids and atherosclerosis risk factors at baseline: the Kuopio Ischaemic Heart Disease Risk Factor (KIHD) study.

*<p>p<0.05.</p><p>Abbreviations as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0064107#pone-0064107-t001" target="_blank">Table 1</a>.</p

Change in IMT_mean (mm) (95% Cl) over 7-years by tertiles of serum carotenoid concentrations, the Kuopio Ischaemic Heart Disease Risk Factor (KIHD) study.

a<p>Adjusted p-value from covariance analysis.</p>b<p>Adjusted for age, examination year, ultrasound sonographer and mean of IMT_mean.</p>c<p>Adjusted for Model 1+BMI, SBP, smoking, physical activity, serum LDL cholesterol, family CHD history and drug for hypertension.</p>d<p>Adjusted for Model 2+hs-CRP (Model 3).</p><p>Abbreviations as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0064107#pone-0064107-t001" target="_blank">Table 1</a>.</p

Inflammation, sauna bathing, and all-cause mortality in middle-aged and older Finnish men: a cohort study

Inflammation and sauna bathing are each related to the risk of all-cause mortality. The interplay between inflammation, sauna bathing and all-cause mortality is not well understood. We aimed to evaluate the separate and joint associations of inflammation (high sensitivity C-reactive protein, hsCRP) and frequency of sauna bathing (FSB) with all-cause mortality in a cohort of Caucasian men. We used the Kuopio Ischaemic Heart Disease Study cohort comprising 2575 men aged 42–61 years at baseline. Serum hsCRP was measured using an immunometric assay and sauna bathing habits were assessed by a self-administered questionnaire. High sensitivity CRP was categorized as normal and high (≤ 3 and > 3 mg/L, respectively) and FSB as low and high (defined as ≤ 2 and 3–7 sessions/week respectively). A total of 1618 deaths occurred during a median follow-up of 27.8 years. Comparing high vs normal hsCRP levels, the multivariable-adjusted HR (95% CI) for all-cause mortality was 1.27 (1.13–1.44). Comparing high vs low FSB, the multivariable-adjusted HR (95% CI) for all-cause mortality was 0.86 (0.76–0.97). Compared with normal hsCRP-low FSB, high hsCRP-low FSB was associated with an increased risk of all-cause mortality 1.28 (1.12–1.47), with no evidence of an association for high hsCRP-high FSB and all-cause mortality risk 1.06 (0.81–1.40). Positive additive and multiplicative interactions were found between hsCRP and FSB in relation to mortality. In a general Finnish male population, both hsCRP and FSB are each independently associated with all-cause mortality. However, frequent sauna baths appear to offset the increased all-cause mortality risk related to high hsCRP levels

Is High Serum LDL/HDL Cholesterol Ratio an Emerging Risk Factor for Sudden Cardiac Death? Findings from the KIHD Study

Aim: Low-density lipoprotein cholesterol (LDL-c) and high-density lipoprotein cholesterol (HDL-c), which are components of total cholesterol, have each been suggested to be linked to the risk of sudden cardiac death (SCD). However, the relationship between LDL-c/HDL-c ratio and the risk of SCD has not been previously investigated. We aimed to assess the associations of LDL-c, HDL-c, and the ratio of LDL-c/HDL-c with the risk of SCD. Methods: Serum lipoprotein concentrations were assessed at baseline in the Finnish Kuopio Ischemic Heart Disease prospective cohort study of 2,616 men aged 42–61 years at recruitment. Hazard ratios (HRs) (95% confidence intervals [CI]) were assessed. Results: During a median follow-up of 23.0 years, a total of 228 SCDs occurred. There was no significant evidence of an association of LDL-c or HDL-c with the risk of SCD. In analyses adjusted for age, examination year, body mass index, systolic blood pressure, smoking, alcohol consumption, physical activity, years of education, diabetes, previous myocardial infarction, family history of coronary heart disease, and serum high sensitivity C-reactive protein, there was approximately a two-fold increase in the risk of SCD (HR 1.94, 95% CI 1.21–3.11; p=0.006), comparing the top (＞4.22) versus bottom (≤2.30) quintile of serum LDL-c/HDL-c ratio. Conclusion: In this middle-aged male population, LDL-c or HDL-c was not associated with the risk of SCD. However, a high serum LDL-c/HDL-c ratio was found to be independently associated with an increased risk of SCD. Further research is warranted to understand the mechanistic pathways underlying this association

Serum carotenoid tertiles by 7-year IMT_max change (adjusted for age, examination year, ultrasound sonographer, BMI, SBP, IMT_max, smoking, serum LDL cholesterol, physical activity, CHD in family, antihypertensive medication and serum hs-CRP.

<p>Probability values are for trend. Carotenoid tertiles (µmol/L): lycopene: ≤0.09, 0.10–0.19, ≥0.20; α-carotene: ≤0.07, 0.08–0.11, ≥0.12; β-carotene: ≤0.26, 0.27–0.41, ≥0.42.</p

Change in IMT_max (mm) (95% Cl) over 7-years by tertiles of serum carotenoid concentrations, the Kuopio Ischaemic Heart Disease Risk Factor (KIHD) study.

a<p>Adjusted p-value from covariance analysis.</p>b<p>Adjusted for age, examination year, ultrasound sonographer and mean of IMT_max.</p>c<p>Adjusted for Model 1 + BMI, SBP, smoking, physical activity, serum LDL-c, family CHD history and drug for hypertension.</p>d<p>Adjusted for Model 2+hs-CRP.</p><p>Abbreviations as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0064107#pone-0064107-t001" target="_blank">Table 1</a>.</p

Inverse association between fasting plasma glucose and risk of ventricular arrhythmias

Aims/hypothesis: In nondiabetic individuals, low values of fasting plasma glucose (FPG) have been associated with an increased risk of cardiovascular events. Identification of the potential mechanisms behind this association could help to elucidate the relationship between glycaemia and cardiovascular disease. We aimed to determine the association between FPG and ventricular arrhythmias. Methods: FPG and other cardiometabolic risk factors were measured in a population-based cohort of 2,482 men without a known history of type 2 diabetes mellitus at baseline. Associations between FPG levels and incident cases of ventricular arrhythmias (ventricular tachycardia or fibrillation events ascertained using the National Hospital Discharge Register) were estimated using Cox regression analysis adjusted for potential confounders. Results: During a median follow-up of 23.3 (interquartile range 18.5–25.3) years, 74 (2.9%) incident events were recorded. In a multivariable analysis adjusted for age, systolic BP, smoking status, LDL- and HDL-cholesterol, and C-reactive protein, the HR for ventricular arrhythmia per 1 mmol/l higher baseline FPG was 0.58 (95% CI 0.34, 0.98); this estimate did not materially change after further adjustment for BMI, alcohol consumption, triacylglycerols and history of ischaemic heart disease (0.50 [95% CI 0.28, 0.89]). Conclusions/interpretation: In this nondiabetic male population, FPG was inversely associated with incident risk of ventricular arrhythmias. While our results could help clarify the relationship between low glucose levels and cardiovascular risk, further studies are required to confirm these findings in other populations