Association of different lipid measures with incident bone fractures: Tehran lipid and glucose study.

OBJECTIVE: To investigate the association between different lipid measures and long-term hospitalization-required incident fracture among Iranian men and women. METHODS: A total of 3309 individuals aged ≥50 years (men = 1598) were included in the study. Multivariate Cox proportional hazard analyses were performed to assess the risk of incident fracture across quintiles, considering first quintile as reference, as well as for 1-standard deviation (SD) increase in each lipid measure, i.e. total cholesterol (TC), triglycerides (TG), low- and high-density lipoprotein cholesterol (LDL-C and HDL-C, respectively), non-HDL-C, and related indices (TG/HDL-C and TC/HDL-C). Covariates included age, body mass index, current smoking, type 2 diabetes mellitus, hypertension, lipid lowering-drugs, and steroid medications (for women). RESULTS: During a median follow-up of 18 years, incident fracture was observed in 201 cases (men = 87). In both gender, no linear association was found between different lipid measures and incident fracture. Among men, only the fourth quartile of TG was associated with lower risk of fracture in the age-adjusted analysis with the hazard ratio (HR) and 95% confidence interval (CI) of [0.45 (0.21-0.95)]. Among women, the age-adjusted HRs and 95% CIs for the second, third, fourth, and fifth quintiles of non-HDL-C were [0.46 (0.25-0.87)], [0.73 (0.42-1.25)], [0.90 (0.54-1.51)], and [0.52 (0.29-0.95)], respectively; the corresponding values in the multivariate model were [0.48 (0.26-0.90)], [0.76 (0.4-1.32)], [0.94 (0.56-1.58)], and [0.52 (0.28-0.95)], respectively. The second quintile of LDL-C was also associated with lower risk for incident fracture in the multivariate analysis [0.53 (0.29-0.98)]. CONCLUSIONS: Among Iranian women, a nonlinear association between non-HDL-C and LDL-C and incident fracture was found as the second and fifth quintile of the former and the second quintile of the latter were associated with about 50% lower risk of fracture. Generally, our findings did not support harmful impact of these lipid measures on incident fracture.

Impact of educational level on incident chronic kidney disease during 13 years of follow-up: a prospective cohort study.

OBJECTIVES: To examine the association between educational level and chronic kidney disease (CKD) among the Iranian population. STUDY DESIGN: This is a prospective cohort study conducted in the framework of the Tehran Lipid and Glucose Study. METHODS: A total of 8173 Iranians (men = 3659) aged ≥20 years were included in the study. CKD was defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. The association between educational status and CKD was explored using multivariate Cox proportional regression analyses, adjusted for age, gender, current smoking, marital status, body mass index, waist circumference, baseline eGFR, diabetes, hypertension, physical activity, history of cardiovascular diseases and dyslipidaemia. RESULTS: During a median follow-up of 13.14 years, 2609 cases of incident CKD were identified; the corresponding incidence rate was 26.35 (range 25.39-27.34) per 1000 person-years. Compared to low educational level, middle and high educational levels showed lower risks for incident CKD in the crude model [hazard ratio (HR) 0.37 (95% confidence interval {CI} 0.34-0.40) and HR 0.40 (95% CI 0.35-0.45), respectively]; however, these HRs changed direction after further adjustment for age and gender [HR 1.26 (95% CI 1.14-1.39) and HR 1.40 (95% CI 1.22-1.61), respectively]. The increased risk of incident CKD for those at higher educational levels remained significant in the fully adjusted model. In addition, results from the gender stratified analyses were in the same direction as those found among the whole study population (P-value for interaction of gender and education >0.8). CONCLUSIONS: Higher educational levels were associated with incident CKD during more than a decade of follow-up; this finding may be attributed to unhealthy lifestyle behaviours among this population group.

Twin's sex and risk of pre-term birth.

Male sex is a risk factor for pre-term birth (PTB) among singleton pregnancies; however, in twin pregnancies, the effect of sex on PTB is not yet clear. The aim of this study was to evaluate the effect of twin's sex on risk of PTB. During this analytical cross-sectional study, we evaluated the effect of twin's sex, chorionicity and other factors on risk of PTB in 676 pregnant women in a university hospital in Tehran, Iran. Existence of male gender in pregnancy was a risk factor for PTB. Comparing same sex twins together, male-male gender was a risk factor for PTB (OR = 1.67 (1.19-2.34), p = 0.002), early PTB (OR = 1.18 (1.04-1.34), p = 0.01) and very early PTB (OR = 1.06 (1-1.13), p = 0.04). Monoamnion twins were at higher risk for early PTB (OR = 1.44 (1.08-1.92), p = 0.02), and very early PTB (OR = 1.95 (1.1-3.44), p = 0.03) but the risk did not increase in monochorion twins. History of abortion was also shown to be a risk factor (p < 0.05). Maternal age, multiparity, body mass index (BMI) and assisted reproductive techniques (ART) did not reach the significance levels to be considered as risk factors.