Antibiotic exposure and potential risk of depression in the Chinese elderly: a biomonitoring-based population study

To examine the associations between urinary antibiotics from various sources and depression in the elderly using the biomonitoring method.

In the current study, we investigated 990 elderly individuals (≥ 60 years old) from a community-based elderly cohort in West Anhui, China. The participants were interviewed by the Geriatric Depression Scale and self-developed questionnaires. A total of 45 antibiotics belonging to nine categories were screened in urine samples by the developed liquid chromatography electrospray tandem mass spectrometry method. Creatinine-corrected concentrations of antibiotics in urines were used to assess their exposure. Logistic regression analysis was employed to test the relationships between exposure to antibiotics and depression.

Compared to the control group, the multinomial logistic regression analyses showed the elderly exposed to higher concentrations of azithromycin (OR = 1.81, 95% CI: 1.09-3.00) and sulfaclozine (OR = 1.54, 95% CI: 1.05-2.28) had increased risks of depression, respectively. After categorizing the detected antibiotics, tetracyclines (OR = 1.48, 95% CI: 1.02-2.16) and veterinary antibiotics (VAs) (OR = 1.53, 95% CI: 1.06-2.20) were positively correlated with increased risks of depression. After stratified by sex, the VAs (OR = 2.04, 95% CI: 1.13-3.71) at higher concentrations were associated with elevated risks of depression in males, while the associations between depression and antibiotic exposures were observed in tetracyclines (OR = 1.74, 95% CI: 1.04-2.85) and all antibiotics (OR = 2.24, 95% CI: 1.01-2.94) at higher levels in females, respectively. Notably, after the stratification by age, the significant associations were mainly present in the subjects under the age of 70.

Our findings reveal that azithromycin, sulfaclozine, tetracyclines, and the VAs were significantly associated with elevated risks of depression in the elderly. Importantly, sex- and age-specific differences were observed in the associations between antibiotic exposures and depression.