Predictors of decline in kidney function in the general population: a decade of follow-up from the Tehran Lipid and Glucose Study

Background and aims We aimed to assess the potential socio-demographic, clinical, and lifestyle-related risk factors for kidney function decline (KFD), defined as >= 30% estimated glomerular filtration rate (eGFR) decline, in an Iranian cohort study. Methods 7190 participants (4049 women) aged 20-90 years with 2-5 eGFR data from examinations (2001-2005 to 2015-2018) were included. Cox proportional hazard models were used to examine the association between potential risk factors and eGFR decline. Results During 11.5 years of follow-up, 1471 (889 women) participants had incident KFD with a crude incidence rate of 192.1 (182.6-202.2) per 10,000 person-year. Among the total population, older age, female gender, prehypertension, hypertension, diabetes, widowed/divorced states, higher triglycerides (TG), prevalent cardiovascular diseases (CVD), and higher baseline eGFR were significantly associated with higher, while moderate physical activity and a positive family history of diabetes were associated with lower risk of KFD (all p values <.05). Prevalent CVD in women but not men, diabetes, and hypertension among postmenopausal than premenopausal women were significant risk factors of KFD. According to the presence of chronic kidney disease (CKD) at baseline, higher eGFR decreased the risk of KFD in patients with CKD and increased KFD risk in those without CKD (all p for interactions <.05). Conclusion KFD is associated with multiple modifiable risk factors among the Iranian urban population that is affected by gender, menopausal status, and initial kidney function. Interventions targeting these factors might potentially help reduce the burden of KFD. Key messages: Menopausal status may influence the relationship between cardiometabolic risk factors and KFD; The impact of higher baseline eGFR on the risk of KFD differed between subjects with preserved kidney function and CKD patients. The interaction between gender, menopausal status, and baseline kidney function with different risk factors on KFD may help to make renal risk prediction scores to identify those in the general population at risk who may benefit from early prevention.