Changes in waist circumference and incidence of chronic kidney disease.

BACKGROUND: Many studies have evaluated the association of anthropometric indices with chronic kidney disease (CKD), but the association of waist circumference(WC) changes with CKD incidence is less clear. We evaluated the effect of WC changes on CKD incidence in participants of the Tehran Lipid and Glucose Study (TLGS). STUDY DESIGN: The risk of CKD incidence was evaluated in three serial phases with interval censoring. A group of 8,183 (46·5% men) participants, mean age 47·4 years, free of previous CKD, were followed. Waist changes were divided into four groups: (i)decrease in WC; (ii) reference group; (iii)mild to moderate increase in WC and (iv)severe increase in WC. Glomerular filtration rate(GFR) was estimated using the MDRD equation. RESULTS: In 8,183 participants, mean GFR was higher in men (77·1 vs. 74·4 mL/min/1·73 m2, P<0·001). During the 9 years of follow-up, 1477 new cases of CKD occurred(1026 in women). WC changes were not associated with the development of CKD in women. In men, decrease in WC was not related to lower risk of CKD (HR: 0·90, 95% CI 0·6-1·4), whereas a mild to moderate increase in WC was associated with a 70% (HR: 1·7, 95% CI 1·3-2·2) higher risk of CKD even after adjusting for covariates (HR: 1·6, 95% CI 1·2-2·2). Severe increase in WC was associated with a fourfold risk of CKD in comparison with reference group (HR: 3·7, 95% CI 2·7-5·1). CONCLUSION: Changes in WC are not independent risk factors for CKD development in women, whereas waist gain can adversely influence the development of CKD in men.

Association between moderate renal insufficiency and cardiovascular events in a general population: Tehran lipid and glucose study.

BACKGROUND: Chronic kidney disease(CKD) has been proposed as a risk factor for cardiovascular disease (CVD). There is conflicting evidence among community based studies regarding the association between CKD and CVD. Furthermore, in order to assess the possible interaction between CKD and BMI, we also examined the association between CKD and CVD, across different BMI categories. METHODS: The risk of CVD events was evaluated in a large cohort of participants selected from the Tehran Lipid and Glucose Study. Participants(mean age, 47.4 years) free of previous CVD were followed up for 9.1 years. GFR ml/min per 1.73 m(2) was estimated using the MDRD formula. RESULTS: Of the 6,209 participants, 22.2%(1381) had CKD with eGFR ml/min per 1.73 m(2) <60 at baseline. Almost all of them (99%) were in stage 3a. Moderate renal insufficiency only predicted CVD outcomes independently when we adjusted for age and sex. After further adjustment, the presence of moderate CKD lost its statistical significance to confer an independent increased risk of CVD events with a hazard ratio of: HR: 1.14, CI 95% 0.91-1.42. Furthermore, when participants were categorized according to CKD status and BMI groups, after further adjustment, no interaction was found(P = 0.2). CONCLUSION: CKD was not an independent risk factor for CVD events in a community-based study in a Tehranian population and the higher prevalence of CVD in subjects with mild to moderate renal insufficiency might be due to the co-occurrence of traditional CVD risk factors in this group.

High prevalence of chronic kidney disease in Iran: a large population-based study.

BACKGROUND: Chronic kidney disease (CKD) is a global public health threat, associated with an alarming increase in morbidity and mortality. The importance is the worldwide increase in its incidence and prevalence. METHODS: In this cross-sectional study, we estimate the prevalence and determine the associated factors of chronic kidney disease in a representative sample of 10063 participants aged over 20 years, in Tehran, Iran. Chronic kidney disease was defined as estimated glomerular filtration rate less than 60 mL/min/1.73 m2. Glomerular filtration rate was estimated from abbreviated prediction equation provided by the Modification of Diet in Renal Disease study (MDRD). RESULTS: Overall prevalence of CKD with the abbreviated MDRD equation was 18.9% (95% confidence interval (CI) 18.2, 20.6). Age adjusted prevalence of CKD was 14.9% (95%CI 14.2, 15.6). Factors associated to CKD include age(years)(odds ratio(OR) 1.1, 95% CI 1.0 to 1.2), female gender (OR 3.1, 95% CI 2.6, 3.7), BMI (BMI 25 to <30 OR 1.5, 95% CI 1.3, 1.8 and BMI > or = 30 OR 1.6, 95% CI 1.3, 2.0), high waist circumference (OR 1.2, 95% CI 1.1, 1.4), hypertension (OR 1.2, 95% CI 1.1, 1.4), and dyslipidemia (OR 1.3, 95% CI 1.1, 1.5). CONCLUSION: CKD with its high prevalence poses a definite health threat in Iran.