Archives of Iranian Medicine
Volume:17 Issue: 6, Jun 2014

Chronic kidney disease is a worldwide public health problem and glomerular filtration rate (GFR), the best overall index of renal function, is most commonly estimated from serum creatinine concentrations. The aim of this study was to determine reference values for serum creatinine concentrations using data from a population-based study in Iran. Serum creatinine was measured using the Jaffe method in 5247 men and women, aged 20–88 years, participants of the Tehran Lipid and Glucose Study. For calculating Jaffe compensated creatinine values in 382 samples, it was measured using both the Jaffe and the enzymatic p-aminophenazone (PAP) methods. Linear regression analysis yielded a regression line equation of Jaffe-creatinine=0.863 × PAP-creatinine + 38.9 μmol/L (r = 0.973, n = 382, P < 0.001). CLSI/IFCC guidelines (International Federation of Clinical Chemistry/ Clinical and Laboratory Standards Institute), non-parametric method was used for determining creatinine reference values. Reference values for serum creatinine ranged between 47–98 μmol/L (0.53–1.11 mg/dL), 37–68 μmol/L (0.42–0.77 mg/dL), and 37–78 μmol/L (0.42–0.88 mg/dL) in men, non-menopausal women, and menopausal women, respectively. Mean serum creatinine concentration was significantly higher in men compared to women for both age ≤ 50 years [70 ± 11 vs. 50 ± 10 μmol/L (0.79 ± 0.12 vs. 0.57 ± 0.11 mg/dL), P < 0.001] and age > 50 years [73 ± 12 vs. 55 ± 12 μmol/L (0.83 ± 0.14 vs. 0.62 ± 0.14 mg/dL), P < 0.001]. Reference values for serum creatinine using the compensated Jaffe method are presented in Iranian subjects, which may help with assessment of kidney function.

Although various anthropometric methods are available for assessing body composition, these have not been compared in Iranian adolescents. The objective of the present study was to compare body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR), waist to height ratio (WHtR) and sum of four skinfolds as predictors of percentage body fat (PBF) and diagnosis of excess adiposity in Iranian adolescents. In this cross-sectional study, all anthropometric measurements were made in133 adolescents (65 boys and 68 girls), aged 10–18 years.PBF was determined using the bioelectrical impedance analysis method. Linear regression and receiver operating characteristic (ROC) analysis were used to analyze the data. Potential covariates including sex, age, and pubertal stage were adjusted. R2adj of models for BMI, WC, WHR, WHtR, and skinfolds were 0.67, 0.56, 0.19, 0.56, and 0.56, respectively (P < 0.001). The AUC value of BMI to differentiate between normal and obese adolescents was 0.92 (P < 0.001). The AUC of BMI was significantly higher than those of WC, WHR, and WHtR (P < 0.05). The performance of BMI is better than other anthropometric indices in predicting PBF and diagnosing excess adiposity in Iranian adolescents.

Menopause is an important milestone of a woman''s reproductive life. There is limited data on the secular trend of menopausal age. The purpose of this study is to identify the secular trend of menopausal age and its related factors among Tehrani women born during 1930 – 1960. A total number of 2266 women, born between 1930and 1960, were recruited among TLGS participants. The World Health Organization classification was used to define menopause status. Birth cohorts were created using 10-year periods, and statistical comparisons were performed with analysis of covariance (ANCOVA). The means for menopausal age of women born in the 1930s, 1940s and 1950s were 48.5, 49.5 and 49.9 years, respectively. After adjustment for possible confounding factors in the linear regression model, the increasing trend of menopausal age was constant (P = 0.029). There is an increasing trend in menopausal age in female residents of Tehran. These findings have implications for endogenous lifetime exposure of women to gonadal steroids.

In this study, we aimed to determine the extent of possible genetic influence on cardio-metabolic risk factors, evaluate the familial aggregation of MetS and estimate the siblings’ recurrence risk ratios in a Tehrani population. In a cross-sectional observational study, we made anthropometric, blood pressure, and biochemical measurements in each member of 566 Tehrani nuclear families. Grandmothers had the highest incidence of atherosclerotic risk factors. Four factors were found which accounted for 77.7% of the overall variance. Recurrence risk ratio among siblings was 5.61 (95% confidence interval [CI]: 3.15–9.97). The adjusted odds ratio (OR) of proband’s MetS status was 1.33 (95% CI: 1.06–1.67). The adjusted OR for the four factors to predict MetS were all significant, with obesity having the highest risk (OR: 7.50, CI: 5.91–9.52), followed by dyslipidemia/hyperglycemia (OR: 4.86, CI: 4.03–5.87), and blood pressure (OR: 4.20, CI: 3.51–5.02). A high risk of MetS (five-fold) was found in siblings with MetS proband. Moreover, findings confirm the importance of obesity for the aggregation of MetS by nearly seven-fold in the study population.

The aim of the study was to evaluate the ability of a low carbohydrate diet score (LCD) to predict the occurrence of the metabolic syndrome (MetS) and its components in a group of Tehrani children and adolescents after 3.6 years of follow-up. Diet scores were calculated using a validated semi-quantitative food frequency questionnaire for participants aged 6–19 years, selected from the Tehran Lipid and Glucose Study cohort. The LCD was calculated based on intake of carbohydrate, monounsaturated fatty acids, refined grains and vegetable protein intake, expressed as a percentage of energy as well as fiber, n3/n6 polyunsaturated fatty acids and glycemic load. The higher the score, the more closely the participant’s diet followed the pattern of LCD. The incidence of MetS and its components was calculated three years later. The mean age of the participants was 13.8 ± 3.6 years and 45.4% were boys. The incidence rates of MetS, high blood pressure, high triglycerides, low HDL-C, abdominal obesity, and high blood glucose were 7.5%, 11%, 15%, 6.9%, 18.3%, and 12.3%, respectively. Compared to those in the lowest quartile of LCD score, after adjusting for age, sex, physical activity, and energy intake, participants in the highest quartile of LCD score had odds ratios of 0.74 (95% CI: 0.24–2.28), 1.16 (95% CI: 0.47–2.81), 0.55(95% CI: 0.21–1.44), 0.49 (95% CI: 0.11–2.08), 0.91 (95% CI: 0.42–1.98), and 1.28 (95% CI: 0.51–3.20) with the incidence of MetS, high blood pressure, high triglycerides, low HDL-C, abdominal obesity, and high blood glucose. No association was found between LCD and the incidence of MetS or its components in children and adolescents in Tehran after 3.6 years of follow up.

Given the lack of data clarifying the manner in which women with metabolic syndrome (MetS) in different eras of their life perceive their health-related quality of life (HRQoL), this study aimed at investigating the association between MetS and HRQoL in reproductive age and post menopausal women. This was a cross-sectional study conducted within the framework of Tehran Lipid and Glucose Study (TLGS). Metabolic syndrome was defined according to the Joint Interim Statement (JIS) and HRQoL was assessed using the Short Form Health Survey (SF-36). Logistic regression analysis was used to estimate the odds ratio (OR) of poor HRQoL with 95% confidence intervals (CIs) for reproductive age and post-menopausal women separately and adjusted for confounding variables. All 603 participants with (n = 340) and without (n = 263) MetS were studied. Overall, in both physical and mental domains, those without MetS had higher scores in all subscales of SF-36 except for vitality, role emotional and mental component summary. Unadjusted odds ratios (95% CI) for poor physical HRQoL were 2.8 (1.7–4.6); (P < 0.001) and 1.5 (0.7–3.4) for the reproductive age and post-menopausal groups, respectively. Compared to the post-menopausal group, the odds ratio of reporting poor HRQoL for reproductive age women was significantly higher, even after adjusting for age (OR: 1.7, 95% CI: 1.0–3.0, P < 0.05). The results indicate that MetS is associated with poor HRQoL in reproductive age, but not in post-menopausal women, and the association is observed mainly in relation to physical rather than mental health.

Neonatal hyperglycemia, which is relatively common in very low birth weight (VLBW) infants, is associated with increased risk of morbidity and mortality. To study the incidence of neonatal hyperglycemia, associated risk factors and the outcome of it in VLBW infants hospitalized in a level III NICU in Tehran. All VLBW newborns admitted to the NICU of Mahdieh Hospital from April 2009 to March 2011 were considered eligible for this retrospective study. All relevant prenatal and perinatal data, as well as details of the hospital stay until discharge or death, were extracted from the case notes and analyzed. Hyperglycemia (blood suger above 150mg/dL) was observed in 179 (31.7%) of the 564 VLBW infants included in the study; 48 infants (26.8%), had received insulin. Risk factors included: low gestational age, (OR = 4.07, 95% CI = 2.09–7.93, P < 0.001), extremely low birth weight (ELBW), (OR = 5.97, 95% CI = 3.77–9.44, P < 0.001), dopamine administration (OR = 2.19, 95% CI = 1.32–3.65, P = 0.003), intralipid (OR = 1.52, 95% CI = 1.04–2.22, P = 0.03), Low APGAR score at 5 minutes (OR = 4.44, 95% CI = 2.48–7.94, P < 0.001), RDS and its complications (OR = 4.20, 95% CI = 2.55–6.93, P < 0.001), were independently associated with hyperglycemia. Other findings with hyperglycemia were: high incidence of IVH >grade II (OR = 2.88, 95% CI = 1.28–6.49, P = 0.01), hospital stay more than 28 days in survivors,(OR = 3.56, 95% CI = 2.02–6.25, P < 0.001), mortality (OR = 4.42, 95% CI = 3.00–6.52, P < 0.001) and more retinopathy of prematurity (ROP ≥ stage II) in survivors (OR = 2.05, 95% CI = 1.11–3.78, P = 0.02). Neonatal hyperglycemia developed in approximately one-third of our VLBW neonates. Relative prevalence and associated findings underscore the need for preventive measures and prompt management.

Consumption of white rice has been proposed as a dietary risk factor for development of metabolic disorders and type 2 diabetes, especially in populations who consume white rice as a staple food. In this study, we investigated the association between consumption of white rice and the occurrence of metabolic syndrome in Tehrani adults after 3 years of follow-up. This longitudinal study was conducted within the framework of the Tehran Lipid and Glucose Study on 1476 adults, aged 19–70 years. Dietary intakes were measured using a validated semi-quantitative food frequency questionnaire at baseline. Biochemical and anthropometric measurements were assessed and documented at baseline (2006–2008) and again 3 years later (2009–2011). Multiple logistic regression models were used to estimate the occurrence of the MetS in each quartile of white rice consumption. The mean age of participants was 37.8 ± 12.3 years, and mean BMI was 26.0 ± 4.5 Kg/m2 at baseline. Participants in the highest quartile of white rice consumption were significantly younger, had lower HDL-C levels, and higher systolic and diastolic blood pressures at baseline (P < 0.01). Higher consumption of white rice was also accompanied by higher increase in serum triglyceride levels after the 3-year follow-up (9.9 ± 2.3 vs. 8.2 ± 2.3%, P < 0.01). After adjustment for all potential confounders, the risk of metabolic syndrome in the highest quartile of white rice consumption compared with the lowest, was 1.66 (95% CI: 1.04–2.66). Moreover, participants with central obesity, low physical activity or low-fiber diet had greater risk of metabolic syndrome if white rice constituted ≥25.6% of total energy. We demonstrated that higher consumption of white rice may be a risk factor for development of metabolic syndrome among Iranian adults.

There is no comprehensive report on seasonal variations in individuals’ blood pressure (BP) in Iranian subjects. The aim of this study is to evaluate individuals’ BP during the four seasons of the year in a large number of adults in Tehran. In a population-based study in Tehran, over a period of ten years (from 1998 to 2011) during the follow up of the four phases of the TLGS, data from a total of 29777 participants aged 20-80 years (42.29% male and 57.71% female) were collected. The participants’ systolic and diastolic BP (SBP and DBP) were measured in every season, and adjusted for weight, age, sex, body mass index, and ambient temperature, history of diabetes mellitus and anti-hypertensive drugs, and their mean SBPs and DBPs were compared. Mean SBP and DBP was 116.79 and 75.29 in spring, 116.11 and 74.81 in summer, 117.45 and 75.95 in fall and 119.03 and 76.28 mmHg in winter. There was a statistically significant difference between mean SBP in summer and winter (P < 0.010). The difference between mean SBP in winter and spring and the difference of mean DBP in winter and summer were near significance level (P = 0.058 and 0.086, respectively). Compared to summer and spring, the individuals’ SBP was higher during winter and their DBP in winter was also higher compared to summer. More attention should be paid to BP measurement in epidemiological studies.

Atherosclerosis is the main cause of death in the world through causing ischemic heart disease (IHD). Altered serum lipid level is the most important risk factor for coronary artery disease (CAD). Many studies reveal a strong inverse association between low levels of high density lipoprotein cholesterol (HDL-C) and increased risk of IHD. On the other hand, plasma levels of HDL-C has a strong hereditary basis. This review focuses on recent data about genetic defects that reduce the level of HDL-C. In order to investigate possible genes linked to low HDL-C disorder, we reviewed previous studies; we searched current medical literature from September 1990 through January 2013 for the genetics causes of low HDL-C levels. Genetic defects in ATP binding cassette protein (ABCA1), apolipoprotein (APO) A1, lecithin cholesteryl acyl transferase, Lipoprotein lipase (LPL), and angiopoietin-like 3 proteins (ANGPTL3) associated with low HDL-C. Other potentially important candidates involved in low HDL-C syndromes are metabolic disorders including sphingomyelin phosphodiesterase 1 and glucocerebrosidase. Also Molecular variations in many genes such as ABCAI and APOAI, TRIB1 and Apo E, lipoprotein lipase (LPL), WW domain-containing oxidoreductase (WWOX), Hepatic lipase (HL), lecithin cholesteryl acyl transferase and some linkage analysis have been associated with reduced HDL-Status. Low HDL-C syndrome has a strong genetic basis and is correlated with an increased risk of CAD.

Multiple Endocrine Neoplasia type IIa (MEN IIa) is an autosomal dominant syndrome characterized by pheochromocytoma, medullary thyroid carcinoma and hyperparathyroidism. Pheochromocytoma occurs in approximately 50% of patients with MEN IIa. This tumor has the capacity to produce ACTH ectopically and manifests as the Cushing syndrome, although it is very rare. We report a 26-year-old woman patient with severe muscle weakness, skin lesions in extremities, hypertension, and new onset diabetes whose laboratory findings included hypokalemia, metabolic alkalosis, high serum level of cortisol, metanephrine, normetanephrine, calcitonin and bilateral adrenal mass in computed tomography as the first clinical manifestations of an ACTH-secreting pheochromocytoma. In the patients with hypertension, new onset diabetes and hypokalemia, the Cushing syndrome and pheochromocytoma should always be ruled out.