Association between obesity with low muscle mass and dialysis mortality.

BACKGROUND/AIM: To examine the association between body composition and dialysis mortality. METHODS: Adult patients who underwent haemodialysis in Taoyuan General Hospital from 2012 to 2016 were enrolled. We reviewed their baseline characteristics and followed up their treatment over 5 years after dialysis. Patients with body mass index >25 kg/m2 were defined as obese. High or low muscle mass were classified by skeletal muscle mass index (SMMI) based on consensus from Chinese population. All age-matched subjects were classified into four groups: (A) optimal; (B) obesity; (C) low muscle mass; and (D) obesity with low muscle mass. Adjusted hazard ratios for mortality and cumulative survival curves were evaluated by Cox proportional hazard model and Kaplan-Meier method. The discriminative power of SMMI was calculated according to the area under the curve and the receiver operating characteristic curve. RESULTS: From a total of 176 age-matched patients, the incidence rates of mortality for different groups were 3.7, 7.8, 10.3 and 16.5 per 1000 person-months. After adjusting for continuous variables, SMMI was independently associated with mortality. The difference between groups A and D was more significant in women than in men after multivariate adjustment (adjusted hazard ratios: 7.465 vs 1.682) (P = 0.035 and 0.553). The discriminative power of SMMI to predict 5-year mortality was 0.700 for men and 0.750 for women, and the best cut-off values were 11.1 and 8.4 kg/m2 CONCLUSIONS: Low muscle mass was associated with dialysis mortality. Obesity with low muscle mass was a predictor for dialysis mortality in women.

High myopia at high altitudes.

Background: Optic nerve sheath diameter (ONSD) increases significantly at high altitudes, and is associated with the presence and severity of acute mountain sickness (AMS). Exposure to hypobaria, hypoxia, and coldness when hiking also impacts intraocular pressure (IOP). To date, little is known about ocular physiological responses in trekkers with myopia at high altitudes. This study aimed to determine changes in the ONSD and IOP between participants with and without high myopia (HM) during hiking and to test whether these changes could predict symptoms of AMS. Methods: Nine participants with HM and 18 without HM participated in a 3-day trek of Xue Mountain. The ONSD, IOP, and questionnaires were examined before and during the trek of Xue Mountain. Results: The ONSD values increased significantly in both HM (p = 0.005) and non-HM trekkers (p = 0.018) at an altitude of 1,700 m. In the HM group, IOP levels were greater than those in the non-HM group (p = 0.034) on the first day of trekking (altitude: 3,150 m). No statistically significant difference was observed between the two groups for the values of ONSD. Fractional changes in ONSD at an altitude of 1,700 m were related to the development of AMS (r pb = 0.448, p = 0.019) and the presence of headache symptoms (r pb = 0.542, p = 0.004). The area under the ROC curve for the diagnostic performance of ONSD fractional changes at an altitude of 1,700 m was 0.859 for predicting the development of AMS and 0.803 for predicting the presence of headache symptoms. Conclusion: Analysis of changes in ONSD at moderate altitude could predict AMS symptoms before an ascent to high altitude. Myopia may impact physiological accommodation at high altitudes, and HM trekkers potentially demonstrate suboptimal regulation of aqueous humor in such environments.