Impact of diabetes mellitus on pneumonia mortality in a senior population: results from the NHANES III follow-up study

OBJECTIVE To examine whether diabetes mellitus increases the risk of pneumonia mortality among seniors in the U.S. general population. METHODS & RESULTS The NHANES III follow-up study data were used. After excluding individuals from other minorities, being hospitalized with pneumonia in the previous year at baseline, or death of pneumonia during the first year of follow-up, a total of 3,707 subjects aged 65 years or older (1,794 men and 1,913 women) who had no missing information on variables for the analysis were included. Approximately 16% of seniors at baseline were diabetics, which was defined as either having been diagnosed by a physician, currently taking pills/insulin lowering blood glucose, or HbA1c higher than 6.4%. During an average 11 years of follow-up, a total of 98 deaths due to pneumonia were recorded (ICD-10: J12-J18). Cox-regression models were used to estimate the risk association between pneumonia mortality and diabetes mellitus. After adjustment for the covariates at baseline, the hazard ratios of pneumonia death were 1.30 (95% CI: 0.64-2.70) for pre-diabetics and 2.28 (95% CI: 1.18-4.39) for diabetics, respectively. Among those covariates, only age (HR (95% CI); 1.16 (1.13-1.20)), gender as female (0.35 (0.22-0.61)) and physical fitness measured as having no problem walking 1(+) mile during the previous month (0.38 (0.20-0.67)) reached statistical significance. CONCLUSIONS The results suggest that diabetes mellitus is a strong risk predictor of pneumonia mortality and the evaluation of physical fitness may also be useful in the risk prediction of pneumonia mortality for seniors.