Weight reduction and the impact on apnea-hypopnea index: A systematic meta-analysis

Obstructive sleep apnea (OSA) is strongly associated with obesity. While the relationship between weight reduction and apnea-hypopnea index improvement has been documented, to our knowledge, it has not been quantified adequately. Therefore, this study aimed to quantify the relationship between weight reduction and AHI change.

METHODS

A systematic literature search was performed using meta-analyses (PRISMA) guidelines for studies reporting AHI and weight loss in people with obesity/overweight and OSA between 2000 and 2023. A linear and quadratic model (weighted by treatment arm sample size) predicted percent change from baseline AHI against mean percent change from baseline weight. The quadratic term was statistically significant (P < 0.05), so the quadratic model (with 95 % prediction interval) was used.

RESULTS

The literature search identified 27 studies/32 treatment arms: 15 using bariatric surgery and lifestyle intervention each and 2 using pharmacological interventions. Included studies were ≥3 months with weight intervention and participants had AHI ≥15/h. Weight reduction in people with OSA and obesity was associated with improvements in the severity of OSA. BMI reduction of 20 % was associated with AHI reduction of 57 %, while further weight reduction beyond 20 % in BMI was associated with a smaller effect on AHI. As the prediction intervals are relatively wide, a precise relationship could not be conclusively established.

CONCLUSION

The degree of AHI index improvement was associated with the magnitude of weight reduction. The model suggests that with progress in weight reduction beyond 20 %, the incremental decrease in BMI appeared to translate to a smaller additional effect on AHI.

Modified Munich chronotype questionnaire for application to short-interval split sleep of non-shift workers

The Munich Chronotype Questionnaire (MCTQ) has been widely validated among various types of populations. However, determination of chronotype among individuals who have a split sleep pattern with short intervals between the first and second sleep bouts on free days has not yet been reported. This study aimed to validate the MCTQ modified for this purpose by assessing the actual sleep-wake timing against the Morningness-Eveningness Questionnaire (MEQ). The modified calculation for the midpoint of sleep on free days (MSF) of the split sleep pattern considers the second sleep bout as the total sleep duration on free days. We recruited 161 participants (mean age: 38.7 ± 7.8 years; 73% females, 29% with split sleep pattern) were recruited to administer the modified version of the MCTQ and MEQ. All of the MCTQ original parameters: midpoint of sleep on work days (MSW, r = -0.575), midpoint of sleep on free days (MSF, r = -0.568), and midpoint of sleep on free days corrected for sleep debt (MSF_sc,r = -0.566) were significantly correlated with MEQ. The MEQ was further tested against MSF in four conditions of the split sleep pattern. The MSF modified for split sleep within 60 minutes after the first awakening showed highest correlation (r = -0.576) against MEQ score. The results demonstrate the modified version of MCTQ is valid to determine the chronotype in participants who practice consolidated and split sleep patterns.