Reader response: Sleep duration, midday napping, and sleep quality and incident stroke: The Dongfeng-Tongji cohort
RicardoLutzky Saute, Neurologist, Department of Neurosciences and Behavioral Sciences, Faculty of Medicine of Ribeirão Preto, University of São Paulo
Submitted January 14, 2020
I read with interest the article by Zhou et al.1 It adds to the body of data evidencing an association between long sleep duration and stroke incidence. However, care must be taken when interpreting the findings. While the authors acknowledge the possibility of this association being an epiphenomenon, the use of phrasings as “detrimental effects” and “consequences” of long sleep duration or napping should be avoided, since they infer a cause.
Obstructive sleep apnea (OSA) is common in elderly, even in those with normal BMI.2 Its association with stroke risk is strong, and there are plausible pathophysiological hypotheses.3 Also, OSA is related to increased sleepiness and is not well predicted by general sleep questionnaires.4 So, it seems more likely that the association of sleep duration and stroke is best explained by a more extensively known factor—as OSA—than by a speculative deleterious direct sleep effect.
Therefore, these findings should not motivate recommendations for reducing sleep duration. Sleep need is highly individualized and sleep deprivation is linked to negative cognitive and metabolic features.5 Further studies should focus on deepening our understating of the nature of this relationship, especially the role of OSA and other sleep disorders.
Disclosure
The author reports no relevant disclosures. Contact journal@neurology.org for full disclosures.
References
Zhou L, Yu K, Yang L, et al. Sleep duration, midday napping, and sleep quality and incident stroke: The Dongfeng-Tongji cohort. Neurology 2019 Epub Dec 11.
Mehra R, Stone KL, Blackwell T, et al. Prevalence and correlates of sleep-disordered breathing in older men: osteoporotic fractures in men sleep study. J Am Geriatr Soc 2007;55:1356–1364.
Sharma S, Culebras A. Sleep apnoea and stroke. Stroke Vasc Neurol 2016;1:185–191.
Laranjeira CM, Barbosa ERF, Rabahi MF. Is subjective sleep evaluation a good predictor for obstructive sleep apnea?. Clinics (Sao Paolo) 2018;73:e355.
Kitamura, S., Katayose, Y., Nakazaki, K. et al. Estimating individual optimal sleep duration and potential sleep debt. Sci Rep 2016;6:35812.
I read with interest the article by Zhou et al.1 It adds to the body of data evidencing an association between long sleep duration and stroke incidence. However, care must be taken when interpreting the findings. While the authors acknowledge the possibility of this association being an epiphenomenon, the use of phrasings as “detrimental effects” and “consequences” of long sleep duration or napping should be avoided, since they infer a cause.
Obstructive sleep apnea (OSA) is common in elderly, even in those with normal BMI.2 Its association with stroke risk is strong, and there are plausible pathophysiological hypotheses.3 Also, OSA is related to increased sleepiness and is not well predicted by general sleep questionnaires.4 So, it seems more likely that the association of sleep duration and stroke is best explained by a more extensively known factor—as OSA—than by a speculative deleterious direct sleep effect.
Therefore, these findings should not motivate recommendations for reducing sleep duration. Sleep need is highly individualized and sleep deprivation is linked to negative cognitive and metabolic features.5 Further studies should focus on deepening our understating of the nature of this relationship, especially the role of OSA and other sleep disorders.
Disclosure
The author reports no relevant disclosures. Contact journal@neurology.org for full disclosures.
References