Chronic kidney disease (CKD) is a significant contributor to global morbidity and mortality. This study investigated disparities in age, sex and socio-economic status in CKD and updated global prevalence estimates through systematic review and meta-analysis.

Five databases were searched from 2014 to 2022, with 14 871 articles screened, 119 papers included and data analysed on 29 159 948 participants. Random effects meta-analyses were conducted to determine overall prevalence, prevalence of stages 3-5 and prevalence in males and females. Influences of age, sex and socio-economic status were assessed in subgroup analyses and risk of bias assessment and meta-regressions were conducted to explore heterogeneity.

The overall prevalence of CKD was 13.0% [95% confidence interval (CI) 11.3-14.8] and 6.6% (95% CI 5.6-7.8) for stages 3-5. The prevalence was higher in studies of older populations (19.3% for stages 1-5, 15.0% for stages 3-5) and meta-regression demonstrated an association of age, body mass index, diabetes and hypertension with prevalence of stages 3-5. The prevalence of CKD stages 1-5 was similar in males and females (13.1% versus 13.2%), but the prevalence of stages 3-5 was higher in females (6.4% versus 7.5%). Overall prevalence was 11.4%, 15.0% and 10.8% in low-, middle- and high-income countries, respectively; for stages 3-5, prevalence was 4.0%, 6.7% and 6.8%, respectively. Included studies were at moderate-high risk of bias in the majority of cases (92%) and heterogeneity was high.

This study provides a comprehensive assessment of CKD prevalence, highlighting important disparities related to age, sex and socio-economic status. Future research should focus on targeted screening and treatment approaches, improving access to care and more effective data monitoring, particularly in low- and middle-income countries.

A plant-based diet has both antioxidant and anti-inflammatory properties. Therefore, it is hypothesized that adherence to a plant-based diet may have a positive effect on kidney function. The study aimed to determine the association between the plant-based diet index (PDI) and chronic kidney disease (CKD).

This cross-sectional analysis used information from the Ravansar noncommunicable diseases cohort study, which included 9,746 participants between the ages of 35 and 65. By measuring the estimation glomerular filtration rate (eGFR) with the modification of diet in the renal disease equation, CKD was determined. Using a food frequency questionnaire, the PDI was computed based on food intake. To determine odds ratios (ORs), multivariable logistic regression models were utilized.

1,058 (10.86%) participants had CKD (eGFR<60 mL/min/1.73 m2), and the mean PDI was 54.22 ± 6.68. The mean eGFR in the group with a high PDI score was significantly higher than the group with a low PDI score (fourth quartile: 79.20 ± 0.36 vs. first quartile: 72.95 ± 0.31, P < .001). Adherence to a plant-based diet was more prevalent in those with a higher socioeconomic status (P < .001). After adjusting for potential confounders, the odds of CKD in the third and fourth quartiles of PDI were 25% (OR: 0.75; 95% confidence interval: 0.62-0.91) and 39% (OR: 0.61; 95% confidence interval: 0.48-0.78, P trend<.001) lower than the first quartile, respectively.

The findings of this study suggest that having a plant-based diet may prevent the prevalent CDK. However, further studies with a cohort design are recommended.

Chronic kidney disease (CKD) is a growing global health problem. Recently, an epidemic of CKD of unknown origin (CKDu), a form of CKD seen mostly in agricultural communities, has been emerged. One of the proposed causes of CKDu is pesticide use in farmers. On the other hand, the research on relation between indoor use of pesticides and CKDu is little. In this study, we aimed to investigate the association between indoor use of pesticide as well as the exposure time with CKDu. This study was done as part of the population-based cohort of Prospective Epidemiological Research Studies in Iran. We used the baseline data of the Zahedan Adult Cohort Study. All subjects with diabetes mellitus and/or hypertension, estimated glomerular filtration rate (eGFR) between 60-89 ml/min/1.73 m2, and unavailable creatinine measurement were excluded. Subjects with an eGFR of less than 60 ml/min/1.73 m2 were defined as having CKDu, and their data were compared with those with an eGFR of more than 90 ml/min/1.73 m2. Data regarding indoor pesticide use and duration of exposure were obtained through a questionnaire. After applying the exclusion criteria, 1079 subjects remained in the study. Female sex, single marital status, low physical activity, triglyceride (TG) levels of more than 150 mg/dl, body mass index (BMI) of more than 25 kg/m2, non-smokers, indoor pesticide use, and high pesticide exposure time were associated with CKDu. The effects of age, female sex, TG levels more than 150 mg/dl, pesticide use (OR 1.36; 95% CI 1.01-1.84), and high exposure time (third tertile of exposure time) compared to non-users (OR 1.64; 95% CI 1.07-2.51) remained significant in multivariable analysis.

We found a positive association between pesticide use, as well as longer exposure time to pesticides, and impaired kidney function in cases without diabetes mellitus and hypertension. Further longitudinal studies should be carried out to confirm these findings.