Prevalence of headaches and their relationship with obstructive sleep apnea (OSA) - Systematic review and meta-analysis

Obstructive sleep apnea (OSA) is one of the most common sleep disorders; however, there are inconsistent results about the connection and occurrence of primary and secondary headaches in OSA. Therefore, the primary objectives were to estimate the prevalence and potential relationship between all types of headaches and OSA. A systematic review was conducted according to PRISMA 2020 guidelines. Studies were searched in PubMed, Embase, and Web of science up to July 2023. The Joanna Briggs Institute tool assessed the risk of bias. 1845 articles were identified, and 23 studies describing 15,402 patients were included. Pooled prevalence of all headaches in OSA was 33% (95% CI: 0.25-0.41), 33% for morning headaches (95% CI: 0.24-0.45), 25% for sleep apnea headaches (95% CI: 0.18-0.34), 19% for tension-type headache (95% CI: 0.15-0.23), and 16% for migraine (95% CI: 0.09-0.26). Relative risk for the occurrence of headache in OSA patients compared to the non-OSA people was 1.43 (95% CI: 0.92-2.25). OSA females and males had morning headaches with similar frequency. The prevalence of headaches in OSA was moderate. OSA did not increase the risk of headache. There is a need to conduct further studies focused on bidirectional connections between sleep disorders and headaches.

Relationship between alcohol and primary headaches: a systematic review and meta-analysis

BACKGROUND

Headache is one of the most common neurological symptoms. Many previous studies have indicated a relationship between primary headaches and alcohol. Drinking has been associated with increased risk of tension-type headache (TTH) and migraine. However, recently published studies have not confirmed this relationship. The existing literature is inconclusive; however, migraine patients avoid alcohol. Therefore, the primary objective was to provide a reliable assessment of alcohol intake in people with primary headaches; the secondary objective was to identify any potential relationship between alcohol consumption and headache risk.

METHODS

This study was based on PubMed, Embase and Web of Science database searches performed on 11 July 2023. This systematic review was registered in PROSPERO (CRD42023412926). Risk of bias for the included studies was assessed using the Joanna Briggs Institute critical appraisal tools. Meta-analyses were performed using Statistica software. The Risk Ratio (RR) was adopted as the measure of the final effect. Analyses were based on a dichotomous division of the respondents into "non-drinkers" and "drinkers" for headache patients and matched non-headache groups.

RESULTS

From a total of 1892 articles, 22 were included in the meta-analysis. The majority demonstrated a moderate or high risk of bias. The first part of the meta-analysis was performed on data obtained from 19 migraine studies with 126 173 participants. The risk of migraine in alcohol drinkers is approximately 1.5 times lower than in the group of non-drinkers (RR = 0.71; 95% CI: 0.57-0.89). The second part involved 9 TTH studies with 28 715 participants. No relationship was found between TTH diagnosis and alcohol consumption (RR = 1.09; 95% CI: 0.93-1.27). Two of the included cluster-headache articles had inconclusive results.

CONCLUSIONS

Alcohol consumption and migraine are inversely correlated. The exact mechanism behind this observation may indicate that migraine leads to alcohol-avoidance, rather than alcohol having any protective role against migraine. There was no relationship between TTH and drinking. However, further studies related to primary headaches and alcohol consumption with low risk of bias are required. Additionally, patients and physicians should consider the latest medical data, in order to avoid the myths about alcohol consumption and primary headaches.

Body temperature set-point and the conscious perception of skin temperature in obese women

Obese and control women were immersed in a bath of water kept at 37 degrees C. Oral temperature was measured. The subjects left hand was placed outside the bath for the local application of thermal stimuli between 20 degrees and 45 degrees C, subjects reporting the most pleasant temperature. The lower oral temperatures and lower levels of skin temperature rated as pleasant by obese women as compared with women of normal body weight or less suggests that in obesity the set-point of body temperature is lowered.