Age, sex, and the association of chronic kidney disease with all-cause mortality in Buddhist priests: An analysis of the standardized mortality ratio from the Korean Buddhist priests cohort

Abstract

Buddhist priests lead a unique lifestyle, practicing asceticism, with a vegetarian diet. Such behavior may have an impact on clinical outcomes. Hence, we explored the mortality among Korean Buddhist priests as compared with the general population.This study is a single-center, retrospective study. Among the 3867 Buddhist priests who visited Dongguk University Gyeongju Hospital between January 2000 and February 2016, 3639 subjects were available for mortality data from Statistics Korea. Standardized mortality ratio (SMR) was computed for all causes of death and compared with the general population using national statistics in Korea. Information regarding end-stage renal disease (ESRD) was investigated from the Korean Society of Nephrology registry. Among the 3639 patients, the baseline laboratory results were obtained in 724 patients. Chronic kidney disease (CKD) was defined as dipstick proteinuria ≥1 or an estimated glomerular filtration rate <60 mL/min/1.73 m.The mean age was 50.0 ± 12.5 years, and 51.0% were men. During the follow-up period for 31.1 ± 35.6 months, 55 (7.6%) patients died. During the follow-up period, 3 (0.4%) and 23 (3.2%) patients developed ESRD and urinary stone, respectively. The SMR for all causes of death was 0.76 (95% confidence interval [CI] 0.57-0.99; men 0.91, 95% CI 0.65-1.23; women 0.52, 95% CI 0.28-0.87). Among 724 patients, 74 (10.2%) patients had CKD. The SMR for non-CKD patients (0.61, 95% CI 0.43-0.85) was significantly lower than the general population. Female and patients older than 50 years (0.74, 95% CI 0.55-0.98) had a significantly lower SMR. In the Cox proportional hazards model with adjustment, older age (adjusted HR 1.04, 95% CI 1.10-1.07) and presence of CKD (adjusted HR 2.55, 95% CI 1.07-6.06) were independently associated with increased all-cause mortality.Buddhist priests and especially Buddhist priests without CKD showed a significantly lower mortality compared with the general population.

Figure 1

Subjects in the study analyses. All Buddhist priests visited Dongguk University Gyeongju Hospital, which was founded by the Korean Buddhism sect, Jogye Order, between January 2000 and February 2016 were evaluated. The mortality data were extracted from a data set of Statistics Korea until December 2014. Renal replacement therapy data were extracted from the Korean Society of Nephrology registry. Among the 3639 patients, the baseline laboratory test results (within 90 days from the first visit), including renal function, were obtained in 724 patients.

Figure 2

All-cause mortality according to sex. Women Buddhist priests showed significantly lower mortality than men (P < .001).