Setor K.Kunutsor, Clinical Academic, University of Bristol
TanjaniinaLaukkanen, Researcher, University of Finland
Jari A.Laukkanen, Cardiologist, Universities of Jyväskylä and Eastern Finland
Submitted June 29, 2018
We thank Dippel et al. for the comment regarding our findings on the association between sauna bathing and risk of stroke. [1] Dippel et al. infer that our findings cannot be generalized to the general population because of healthy volunteer bias and the use of a reference group who were not sauna-naive. Indeed, observational cohort studies cannot prove causality as they are beset with biases such as selection bias, reverse causation, residual confounding, and regression dilution bias. However, several strengths of our study deserve mention. Our study participants were based on a random sample recruited from the general population; our results remained robust on excluding the first 2 years of follow-up or participants with pre-existing disease; there was adjustment for a comprehensive panel of potential confounders; the results were consistent in further analysis that used, as a reference comparison, a combination of participants who did not use sauna baths and participants who had a single sauna session per week. Furthermore, there is extensive evidence on the beneficial effects of sauna exposure on blood pressure, inflammation, oxidative stress, circulating lipids, arterial stiffness, and vascular resistance; [2,3] pathways implicated in the pathophysiology of stroke, Alzheimer’s disease, and respiratory conditions. [4,5]
1. Kunutsor SK, Khan H, Zaccardi F, Laukkanen T, Willeit P, Laukkanen JA. Sauna bathing reduces the risk of stroke in finnish men and women: A prospective cohort study. Neurology 2018;90:e1937-e1944.
2. Laukkanen JA, Laukkanen T, Kunutsor SK. Cardiovascular and other health benefits of sauna bathing: A review of evidence. Mayo Clin Proc 2018 (in press).
3. Kunutsor SK, Laukkanen T, Laukkanen JA. Longitudinal associations of sauna bathing with inflammation and oxidative stress: The KIHD prospective cohort study. Ann Med Epub 2018 Jun 13.
4. Breteler MM. Vascular risk factors for Alzheimer's disease: an epidemiologic perspective. Neurobiol Aging 2000;21:153-160.
5. Huang Y, Cai X, Li Y, et al. Prehypertension and the risk of stroke: a meta-analysis. Neurology 2014;82:1153-1161.
We thank Dippel et al. for the comment regarding our findings on the association between sauna bathing and risk of stroke. [1] Dippel et al. infer that our findings cannot be generalized to the general population because of healthy volunteer bias and the use of a reference group who were not sauna-naive. Indeed, observational cohort studies cannot prove causality as they are beset with biases such as selection bias, reverse causation, residual confounding, and regression dilution bias. However, several strengths of our study deserve mention. Our study participants were based on a random sample recruited from the general population; our results remained robust on excluding the first 2 years of follow-up or participants with pre-existing disease; there was adjustment for a comprehensive panel of potential confounders; the results were consistent in further analysis that used, as a reference comparison, a combination of participants who did not use sauna baths and participants who had a single sauna session per week. Furthermore, there is extensive evidence on the beneficial effects of sauna exposure on blood pressure, inflammation, oxidative stress, circulating lipids, arterial stiffness, and vascular resistance; [2,3] pathways implicated in the pathophysiology of stroke, Alzheimer’s disease, and respiratory conditions. [4,5]
1. Kunutsor SK, Khan H, Zaccardi F, Laukkanen T, Willeit P, Laukkanen JA. Sauna bathing reduces the risk of stroke in finnish men and women: A prospective cohort study. Neurology 2018;90:e1937-e1944.
2. Laukkanen JA, Laukkanen T, Kunutsor SK. Cardiovascular and other health benefits of sauna bathing: A review of evidence. Mayo Clin Proc 2018 (in press).
3. Kunutsor SK, Laukkanen T, Laukkanen JA. Longitudinal associations of sauna bathing with inflammation and oxidative stress: The KIHD prospective cohort study. Ann Med Epub 2018 Jun 13.
4. Breteler MM. Vascular risk factors for Alzheimer's disease: an epidemiologic perspective. Neurobiol Aging 2000;21:153-160.
5. Huang Y, Cai X, Li Y, et al. Prehypertension and the risk of stroke: a meta-analysis. Neurology 2014;82:1153-1161.
For disclosures, please contact the editorial office at journal@neurology.org.