Assessment of overweight and obesity in Iranian adolescents: optimal cut-off values of anthropometric indices

Background: Various indices have been used to estimate overweight and obesity; all have limitations and strengths. The prevalence of overweight and obesity may differ by ethnicity.

Aims: This study evaluated waist circumference [WC], waist-to-hip ratio [WHpR], waist-to-height ratio [WHtR] and neck circumference [NC] as reliable alternatives to body mass index for screening for overweight and obesity, and determined their optimum cut-off values in different ethnic groups.

Methods: The study was conducted from November 2015 to February 2016 among adolescents aged 12–14 years from five ethnicities in the Islamic Republic of Iran: Arab, Kurdish, Sistani and Baluchi, Turkish and Turkman. Stratified multistage sampling was used to select 2444 students. Receiver operating characteristic curves were constructed to evaluate WC, WHpR, WHtR and NC as screening indices for overweight and obesity as categorized by body mass index centiles.

Results: The prevalence of overweight and obesity in the total sample were 15.3% and 9.2% respectively, with higher rates in students of Arab, Kurdish and Turkish ethnicity. The areas under curve ranged from 0.8 to 0.9 for WC, WHtR and NC. The mean optimum values with the highest sensitivity and specificity to identify overweight were: 72.3 cm [sensitivity 0.80, specificity 0.75] for WC, 0.46 [0.85, 0.70] for WHtR and 31 cm [0.76, 0.76] for NC. For obesity mean optimum values were: 77 cm [0.84, 0.81] for WC, 0.50 [0.84, 0.84] for WHtR and 31.5 cm [0.88, 0.71] for NC.

Conclusions: WC, WHtR and NC may be useful tools to screen for adiposity using their optimum values for sex and ethnicity

Northern Iranian growth charts for children aged 7–11 years: comparison with international reference curves

Background: Child body mass index [BMI] is an internationally accepted indicator to assess child health status. International BMI reference curves are available but their suitability for Iranian children in not known.

Aims: This study aimed to produce BMI-for-age growth curves for northern Iranian schoolchildren aged 7–11 years and compare them with the World Health Organization [WHO 2006] and Centers for Disease Control and Prevention [CDC 2000] reference curves.

Methods: Stratified multistage cluster sampling was used to select schoolchildren from urban and rural areas of Babol. Height and weight were measured and BMI calculated. Smoothed BMI-for-age growth curves were constructed for both sexes and compared with the WHO and CDC reference curves.

Results: A total of 4 083 children aged 7–11 years were included; 48.8% were boys and 56.7% were urban residents The major significant differences between the Iranian curves in this study and the CDC2000 and WHO 2006 growth charts were in the upper centiles. The 5th centile is close to the 5th centiles of the reference curves.

Conclusions: BMI centiles for 7–11 years schoolchildren in Babol differed significantly from the international growth reference curves. Therefore, local and population-specific BMI curves should be developed to assess physical growth of children.

HTLV-1: ancient virus, new challenges

Human T-lymphotropic virus [HTLV-1] is an ancient pathogen for human being but arising and recognized recently. The routes of transmission are vertical [mainly by breastfeeding], unsafe sexual contacts and through contaminated blood components specially in whom need frequent and repeated blood transfusions such as permanent anemia due to blood loss in hemophilia and major thalassemia. Patients who should undergo hemodialysis in their lifelong are another instance for increased risk of HTLV-1 exposure. The main HTLV-1-associated diseases are tropical spastic tetraparesis [HAM/TSP], an inflammatory myelopathy and adult T-cell leukemia [ATL]. Although HTLV-1 is scattered around the world, only in endemic areas where prevalence rate is more than 1%, viral burden of infection have accumulated. Japan, Southern and Central parts of Africa, Caribbean basin and Iran are examples of endemic areas of HTLV-1. In this article, a rapid and brief review of HTLV-1 virology, immunology and pathogenesis have emerged. In addition, a short debate has driven about current statues of HTLV-1 in Iran

relationship between renal artery stenosis and ischemic nephropathy

Ischemic nephropathy is defined as a clinically significant progressive reduction in glomerular filtration rate that is usually associated with significant renal artery stenosis [unilateral or bilateral involvement]. Atherosclerotic renal artery disease is known as the most common cause of the ischemic nephropathy. These patients may develop secondary hypertension. In addition, epidemiologic data has showed a clear association between atherosclerotic renal artery stenosis and coronary artery disease and other cardiovascular disease. Despite the preserving function of kidney on various autoregulation processes, unusual microvascular function will be resulted due to sustained decline in renal perfusion. The ischemic nephropathy of asymptomatic cases may result in renovascular hypertension and renal failure. The reduction of renal function in these patients might be decreased or stopped by early appropriate diagnosis and also might be treated with renal artery angioplasty or surgery, after medical management. There is a debate about the occurrence of ischemic nephropathy as a result of atherosclerotic renal artery stenosis. In this study we aimed to review the prevalence of ischemic nephropathy due to atherosclerotic renal artery stenosis

Helicobacter Pylori infection and metabolic parameters: is there an association in elderly population?

The association between Helicobacter pylori [HP], as one of the most prevalent infections, and serum glucose level was inconsistent with previous studies. Moreover, there are contradictory reports about the relationship between HP infection and lipid profile. The purpose of this study was to determine the relationship between HP infection with glycemic and lipid profiles in elderly people. This cross-sectional study was conducted on 1,300 subjects over 60 years in Amirkola Health and Ageing Project. After using a standard questionnaire, the venous sampling was done to determine FBS, triglyceride [TG], cholesterol, low density lipoprotein [LDL], high-density lipoprotein [HDL] and IgG anti-HP after a 12-h overnight fast. The information about the individuals was analyzed using SPSS-17. The P < 0.05 was considered statistically significant. The prevalence of HP infection in diabetic and nondiabetic subjects was 77.5% and 75.7%, respectively, which had no statistically significant difference. Also, there was no significant difference between the serum lipid level including TG, LDL and HDL cholesterol with levels of anti-HP antibodies. The rate of HP infection in patients with hypertension was 75% and 78.3% in healthy patients, in which the difference was not statistically significant. In terms of body mass index [BMI], the prevalence of infection in the group with normal BMI was 77.3% and for the overweight and obese elderly population, it was 74.7%, and 77.5%, respectively [P = 0.445]. The findings revealed that in a large population of elderly in the northern part of Iran, HP infection is not associated with BMI, serum glucose and lipid profile as well as blood pressure

Factors affecting survival of patients with oesophageal cancer: a study using inverse Gaussian frailty models

<p><b>INTRODUCTION</b>Oesophageal cancer is one of the most common causes of cancer mortality in developing countries, including Iran. This study aimed to assess factors affecting survival of patients with oesophageal cancer using parametric analysis with frailty models.</p><p><b>METHODS</b>Data on 359 patients with oesophageal cancer was collected from the Babol Cancer Registry for the period 1990-1991. By 2006, the patients had been followed up for a period of 15 years. Hazard ratio was used to interpret the risk of death. To explore factors affecting the survival of patients, log-normal and log-logistic models with frailty were examined. The Akaike Information Criterion (AIC) was used for selecting the best model(s). Cox regression was not suitable for this patient group, as the proportionality assumption of the Cox model was not satisfied by our data (p = 0.007).</p><p><b>RESULTS</b>Multivariate analysis according to parametric models showed that family history of cancer might increase the risk of death from cancer significantly. Based on AIC scores, the log-logistic model with inverse Gaussian frailty seemed more appropriate for our data set, and we propose that the model might prove to be a useful statistical model for the survival analysis of patients with oesophageal cancer. The results suggested that gender and family history of cancer were significant predictors of death from cancer.</p><p><b>CONCLUSION</b>Early preventative care for patients with a family history of cancer may be important to decrease the risk of death in patients with oesophageal cancer. Male gender may be associated with a lower risk of death.</p>

[Affecting factors on survival of patients with gastric cancer using frailty model]

In survival analysis because are still unknown some of the important factors related to disease, it is too difficult or impossible measure all the appropriate factors and related diseases. Not consider these common unknown risk factors causes dependence among survival times, the results from Cox proportional hazard model and parametric models are not reliable. In this case, we use to confront the above problem of frailty models. The purpose of this study was to examine factors affecting survival of patients with gastric cancer using the log-logistic parametric model with gamma frailty and to compare these results with Cox model. This study includes Information of 110 cases with gastric cancer was collected from Babol cancer registry during 1990 through 1991, who were followed up for a period of 15 years by the year 2006. In order to explore factors affecting survival of patients, Cox model and also parametric model Log-logistic with gamma frailty were examined and the Akaike information criterion [AIC] was considered as a criterion to select the best model [s]. For the statistical analysis, the statistical softwares SAS 9.1 and STATA 8.0 were used. All P<0.05 were defined as statistical significance. Sample of subjects encompassed 75.4% men and 24.6% women. The mean age at diagnosis was 60.2 yr for men and 57.5 yr for women. The median survival time reached 8.6 months, and survival rates in 1, 3, and 5 years following diagnosis were 25%, 18%, and 17%, respectively. Multivariate analysis showed that family history of cancer might increase significantly the risk of death from cancer according to Cox and parametric models by including and not including heterogeneity effect. According to AIC criterion and the nature of the data [hazard rate is non-monotonic], parametric model [with and without gamma frailty] had better performance when compared to Cox model. And among, log logistic model with gamma frailty seemed more appropriate. In this model, age and family history of cancer were significant predictors. Results indicated that early preventative care for patients with family history of cancer might be of importance to decrease the risk of death in patients with gastric cancer, and being younger, on the other hand, would cause a potential decline in the corresponding risk of death. According to our findings, based on the Akaike criterion and also the nature of the data [the hazard rate is hump-shaped], log logistic model with gamma frailty could be considered as a useful statistical model in survival analysis of patients with gastric cancer rather than Cox model