Dietary omega-6/omega-3 fatty acids and risk of prostate cancer; Is there any potential interaction by organophosphate insecticides among the agricultural health study population.

BACKGROUND: In the United States (US), the average annual increase in the incidence of prostate cancer (PCa) has been 0.5% between 2013 and 2017. Although some modifiable factors have been identified as the risk factors for PCa, the effect of lower ratio of omega-6 to omega-3 fatty acids intake (N-6/N-3) remains unknown. Previous studies of the Agricultural Health Study (AHS) reported a significant positive association between PCa and selected organophosphate pesticides (OPs) including terbufos and fonofos. OBJECTIVE: The aim of this study was to evaluate the association between N-6/N-3 and PCa and any interaction between N-6/N-3 and 2 selected OPs (i.e., terbufos and fonofos) exposure. DESIGN AND PARTICIPANTS: This case-control study, nested within a prospective cohort study, was conducted on a subgroup of the AHS population (1193 PCa cases and 14,872 controls) who returned their dietary questionnaire between 1999 and 2003 MAIN OUTCOME MEASURES: PCa was coded based on the International Classification of Diseases of Oncology (ICD-O-3) definitions and obtained from the statewide cancer registries of Iowa (2003-2017) and North Carolina (2003-2014). STATISTICAL ANALYSIS: Multivariate logistic regression analysis was applied to obtain the odds ratios adjusted (aORs) for age at dietary assessment (years), race/ethnicity (white, African American, other), physical activity (hours/week), smoking (yes/no), terbufos (yes/no), fonofos (yes/no), diabetes, lycopene intake (milligrams/day), family history of PCa, and the interaction of N-6/N-3 with age, terbufos and fonofos. Pesticide exposure was assessed by self-administrated questionnaires collecting data on ever/never use of mentioned pesticides during lifetime as a yes/no variable. Assessing the P value for the interaction between pesticides and N-6/N-3, we used the continuous variable of "intensity adjusted cumulative exposure" to terbufos and fonofos. This exposure score was based on duration, intensity and frequency of exposure. We also conducted a stratified regression analysis by quartiles of age. RESULTS: Relative to the highest N-6/N-3 quartile, the lowest quartile was significantly associated with a decreased risk of PCa (aOR=0.61, 95% CI: 0.41-0.90), and quartile-specific aORs decreased toward the lowest quartile (Ptrend=<0.01). Based on the age-stratified analysis, the protective effect was only significant for the lowest quartile of N-6/N-3 among those aged between 48 and 55 years old (aORs=0.97, 95% CI, 0.45-0.55). Among those who were exposed to terbufos (ever exposure reported as yes in the self-report questionnaires), lower quartiles of N-6/N-3 were protective albeit nonsignificant (aORs: 0.86, 0.92, 0.91 in quartiles 1,2, and 3, respectively). No meaningful findings were observed for fonofos and N-6/N-3 interaction. CONCLUSION: Findings showed that lower N-6/N-3 may decrease risk of PCa among farmers. However, no significant interaction was found between selected organophosphate pesticides and N-6/N-3.

Changes in Bone Turnover, Inflammatory, Oxidative Stress, and Metabolic Markers in Women Consuming Iron plus Vitamin D Supplements: a Randomized Clinical Trial.

We aimed to investigate whether combination of vitamin D and iron supplementation, comparing vitamin D alone, could modify bone turnover, inflammatory, oxidative stress, and metabolic markers. Eighty-seven women with hemoglobin (Hb) ≤ 12.7 g/dL and 25OHD ≤ 29 ng/mL vitamin D deficiency/insufficiency aged 18-45 years were randomly assigned into two groups: (1) receiving either 1000 IU/day vitamin D3 plus 27 mg/day iron (D-Fe); (2) vitamin D3 plus placebo supplements (D-P), for 12 weeks. In D-Fe group, significant decrease in red blood cells (RBC) (P = 0.001) and hematocrit (Hct) (P = 0.004) and increases in mean corpuscular hemoglobin concentration (MCHC) (P = 0.001), 25OHD (P < 0.001), osteocalcin (P < 0.001), high-density cholesterol (HDL) (P = 0.041), and fasting blood sugar (FBS) (P < 0.001) were observed. D-P group showed significant decrease in RBC (P < 0.001), Hb (P < 0.001), Hct (P < 0.001), mean corpuscular volume (MCV) (P = 0.004), mean corpuscular hemoglobin (MCH) (P < 0.001), MCHC (P = 0.005), serum ferritin (P < 0.001), and low-density cholesterol (LDL) (P = 0.016) and increases of 25OHD (P < 0.001), osteocalcin (P < 0.001), C-terminal telopeptide (CTX) (P = 0.025), triglyceride (TG) (P = 0.004), FBS (P < 0.001), and interleukin-6 (IL-6) (P = 0.001) at week 12. After the intervention, the D-P group had between-group increases in mean change in the osteocalcin (P = 0.007) and IL-6 (P = 0.033), and decreases in the RBC (P < 0.001), Hb (P < 0.001), Hct (P < 0.001), and MCV (P = 0.001), compared with the D-Fe group. There were significant between-group changes in MCH (P < 0.001), MCHC (P < 0.001), ferritin (P < 0.001), and serum iron (P = 0.018). Iron-vitamin D co-supplementation does not yield added benefits for improvement of bone turnover, inflammatory, oxidative stress, and metabolic markers, whereas, vitamin D alone may have some detrimental effects on inflammatory and metabolic markers. IRCT registration number: IRCT201409082365N9.

Vitamin D supplementation improves SIRT1, Irisin, and glucose indices in overweight or obese type 2 diabetic patients: a double-blind randomized placebo-controlled clinical trial.

BACKGROUND: Vitamin D (VD) may increase sirtuin 1 (SIRT1) and subsequently PPAR-γ coactivator 1α (PGC-1α) and irisin levels and these improvements may reduce insulin resistance (IR). The aim was to assess the effects of vitamin D supplementation on SIRT1, irisin, and IR in overweight/obese type 2 diabetes (T2D) patients. METHODS: Ninety T2D males and females were recruited as a clinical trial study (mean of age and body mass index (BMI) of intervention and placebo groups were 50.05 ± 10.17 and 50.36 ± 10.2 yrs. and 31.37 ± 3.4 and 30.43 ± 3.2 kg/m2, respectively). The inclusion criteria were T2D, VD deficient, BMI > 25 kg/m2, and serum HbA1c < 8.5%. The exclusion criteria were using vitamin and mineral supplements, having any acute disease, recent modifying dose or type of drugs. The supplementation was 50,000 IU/week VD or placebo for 8 weeks. The demographic characteristics, anthropometrics, dietary intakes and physical activity status, sun exposure status, fasting blood sugar (FBS) and insulin, glycosylated hemoglobin (HbA1c), irisin, SIRT1, 25-hydroxy D3 (25(OH)VD), homeostasis model assessment of insulin resistance (HOMA-IR), and quantitative insulin sensitivity check index (QUICKI) were determined. The significant P-value was ≤0.05. RESULTS: The increase of serum VD, SIRT1, and irisin in the intervention group was significant (p < 0.001). HbA1c was decreased significantly by 1%. The changes in the other glucose indices (FBS, insulin, and IR) were non-significant. CONCLUSIONS: VD supplementation may improve T2D by decreasing HbA1c and increasing SIRT1 and irisin in VD deficient T2D patients. Further trials are suggested. TRIAL REGISTRATION: Iranian Registry of Clinical Trials, IRCT201604202365N11. Registered 21/08/2016, http://en.irct.ir/trial/2019.

Comparing the effectiveness of vitamin D plus iron vs vitamin D on depression scores in anemic females: Randomized triple-masked trial.

Background: Low levels of 25-hydroxyvitamin D (25(OH)D) have been related to depression and anxiety. It seems that anemia is associated with vitamin D deficiency. We aimed to evaluate the effects of iron-vitamin D co-supplementation versus vitamin D alone on depression scores in anemic females with low levels of serum 25-hydroxyvitamin D. Methods: This randomized controlled trial was conducted on eighty premenopausal females who were recruited between May 2015 and October 2015 from primary health care centers. Women with anemia and low concentrations of 25(OH)D were randomized to either 1000 IU/d vitamin D plus 27 mg/d iron (D-Fe) or vitamin D plus placebo supplements (D-P) for 12 weeks. Depressive and anxious symptoms were evaluated with the Beck Depression Inventory (BDI) with subscales 1-13 and 14-21 and Beck Anxiety Inventory (BAI). To compare the groups, Mann-Whitney or chi-squared tests were used and within groups comparison was performed using Wilcoxon signed ranks test. The study was registered on www.clinicaltrial.org as NC 01876563. Results: The serum concentrations of 25(OH)D were increased significantly in both groups at the end of the study. In both groups, there was a significant improvement in total BDI, the BDI subscale, and the BAI scores (p<0.001). No differences were found between groups (p>0.05). Conclusion: Although the potential positive effect of vitamin D on mental health was evident, iron plus vitamin D co-supplementation did not demonstrate any significant benefits over vitamin D alone, neither in depression score reduction nor anxiety symptoms.

Vitamin D supplementation and serum heat shock protein 60 levels in patients with coronary heart disease: a randomized clinical trial.

BACKGROUND: The aim in this study was to investigate the effect of vitamin D (25(OH)D3) supplementation on heat shock protein 60 (HSP 60) and other inflammatory markers (IL-17, TNF-α, PAB) in patients with coronary heart disease (CHD). METHODS: In this double-blind, randomized clinical trial, we recruited 80 male and female patients aged 30-60 with CHD and 25(OH)D3 serum levels < 30 ng/ml from Rasool-e-Akram Hospital in Tehran, Iran. Serum levels of HSP 60 as primary outcome, and 25(OH)D3, IL-17, TNF-α, PAB, lipid profiles and parathyroid hormone (PTH) as secondary outcomes were measured at baseline and post-intervention. We randomly assigned eligible participants to a placebo group (N = 40) or an intervention group (N = 40) (50,000 IU/wk. vitamin D supplement) for eight weeks. RESULTS: The results demonstrated that vitamin D supplementation resulted in a significant increase in 25(OH) D3 serum levels in the intervention group compared to the placebo group (46.86 vs. 7.28 ng/ml). PTH levels decreased in the intervention group compared to the placebo group (- 19.81 vs. 2.92 pg/ml) after eight weeks of supplementation. Furthermore, we observed a significant change in waist circumference (- 0.97 vs. -0.26 cm), fat percentage (-.13 vs. 0.1%), systolic blood pressure (- 3.85 vs. -2.11 mmHg) and diastolic blood presure (- 4 vs. -1.86 mmHg) in the vitamin D group compared to the placebo group (all P values < 0.05). Other variables did not significantly change after the intervention. CONCLUSION: Based on our findings, weekly vitamin D supplementation of 50,000 IU for eight weeks in patients with CHD resulted in decreased systolic and diastolic blood pressure, waist circumference and fat percentage. No significant effect on HSP 60, inflammatory markers or lipid profiles was observed. TRIAL REGISTRATION: IRCT, IRCT201612122365N14. Registered 12 December 2016.

A double blind randomized clinical trial to investigate the effect of vitamin D supplementation on metabolic and hepato-renal markers in type 2 diabetes and obesity.

Background: According to the recent studies, vitamin D deficiency has been correlated with progress in type 2 Diabetes and Metabolic Syndrome. The aim of this study was to assess the effect of vitamin D supplementation on glucose and lipid profiles, blood pressure, and biomarkers of liver and kidney in type 2 diabetic patients. Methods: In this Double blinded randomized clinical trial, 90 patients with type 2 diabetes and serum 25-Hydroxy vitamin D levels of less than 30 ng/ml recruited from "Besat Diabetes Clinic" in Rasht, North of Iran. The subjects took 50000 IU vitamin D supplements or placebo for 8 weeks. We assessed the levels of serum 25 (OH) vitamin D, glucose and lipid profiles, oxidative and inflammatory indices, liver and kidney biomarkers, blood pressure, and sun exposure time, physical activity before and after intervention, and compared them between cases and controls. Results: Vitamin D supplementation significantly increased serum vitamin D level, Superoxide Dismutase (SOD) activity, and significantly decreased serum HbA1C (Glycosylated Hemoglobin) level (p<0.001). High Density Lipoprotein (HDL) Cholesterol increased significantly (p=0.016), and Erythrocyte Sedimentation Rate (ESR) significantly decreased (p=0.039) after the intervention. Conclusion: Our results represented that weekly supplementation with 50000 IU vitamin D for 8 weeks may be effective by improving HbA1C and lipid profile in type 2 diabetes mellitus.

Associations of Baltic Sea and Mediterranean dietary patterns with bone mineral density in elderly women.

OBJECTIVE: Dietary quality in relation to bone health has been analysed in relatively few studies. The current study aimed to assess the association of the Baltic Sea diet (BSD) and the Mediterranean diet (MD) with bone mineral density (BMD) among elderly women. DESIGN: Lumbar, femoral and total body BMD were measured by dual-energy X-ray absorptiometry at baseline and year 3. Dietary intake was measured by 3 d food record at baseline. BSD and MD scores were calculated from food and alcohol consumption and nutrient intake. Information on lifestyle, diseases and medications was collected by questionnaires. Longitudinal associations of BSD and MD scores with BMD were analysed using linear mixed models. SETTING: Interventional prospective Kuopio Osteoporosis Risk Factor and Fracture Prevention study including women aged 65-71 years and residing in Kuopio province, Finland. SUBJECTS: Women (n 554) with mean age of 67·9 (sd 1·9) years and mean BMI of 28·8 (sd 4·7) kg/m2. RESULTS: Higher BSD scores were associated with higher intakes of fruit and berries, vegetables, fish and low-fat dairy products, and lower intake of sausage. Higher MD scores were associated with higher consumption of fruit and berries and vegetables. BSD and MD scores were associated with higher PUFA:SFA and higher fibre intake. Femoral, lumbar or total body BMD was not significantly different among the quartiles of BSD or MD score. CONCLUSION: The lack of associations suggest that Baltic Sea and Mediterranean dietary patterns may not adequately reflect dietary factors relevant to bone health.

Effects of Maternal Diet During Pregnancy on the Risk of Childhood Acute Lymphoblastic Leukemia: A Systematic Review.

Acute lymphoblastic leukemia (ALL) is the most common type of leukemia in children that can be affected by maternal diet. The aim of this study was to evaluate maternal dietary risk factors of ALL. We searched MEDLINE, Cochrane Library, Springer Link, Wiley Online, Science Direct, Mosby, ISI Web of Science, OVID, ProQuest, and Scopus from database inception until February 2, 2016. Two reviewers scanned titles, abstracts, and keywords of articles after excluding duplicates. We included case-control studies evaluating the relationship between maternal diet during pregnancy and childhood ALL. The search resulted in 2,940 papers, of which 11 full-text articles met the criteria for inclusion in the review and were analyzed. The finding of these studies suggest that maternal diet composed largely of vegetables, fruits, and protein sources before and during pregnancy can reduce the risk of ALL in offspring. Maternal alcohol intake had no effect. Nevertheless, inherent limitations of case-control studies like measurement error, random error, recall bias, and selection bias preclude conclusive evidence. Persuading pregnant women to follow a healthy diet rich in fruits, vegetables, and protein may reduce the risk of childhood ALL. Avoiding alcohol intake seems prudent.

Domestic violence against women as a risk factor for depressive and anxiety disorders: findings from domestic violence household survey in Tehran, Iran.

Domestic violence (DV) especially intimate partner violence is a global health problem responsible for significant part of burden of diseases in women. Mental health problems such as depression and anxiety are possibly results and resulted in IPV. To investigate correlation between IPV and depression and anxiety among married women, in a household survey of married women in Tehran, Iran, at summer 2011, we recruited 615 samples with cluster sampling method and they are directly asked about experience of 23 different types of physical and non-physical IPV during marital life and last 12 months. Depression and anxiety were assessed by Beck depression inventory II (BDI) and Beck Anxiety inventory (BAI). Multinominal regression model was used to assess the independent relationship of factor on IPV. Mean (±SE) age and duration of marriage were 42.6 ± 0.9 and 22 ± 0.8, respectively. Non-physical violence and physical violence during marital life reported in 77.2 and 35.1 %. Clinically significant depression and anxiety was reported in 15.3 and 32.7 % of women, respectively. The odds ratio (95 % CI) of clinically significant depression and anxiety in DV victims were 5.8 (2.3-14.6) and 2.6 (1.6-4.3). DV as a social factor is significantly correlated factor with depression and anxiety. Comprehensive view and collaborative work to detect and address social determinants of mental illness like DV is a crucial point in mental health promotion programs.

Is exclusive breastfeeding and its duration related to cardio respiratory fitness in childhood?

AIMS AND OBJECTIVE: This study investigated the effect of breastfeeding on cardio respiratory fitness (CRF) in students of Kermanshah, Iran. METHODS AND MATERIALS: In this retrospective cohort study, 246 students with the mean ± SD age of 7.28 ± 0.50 years, mean breastfeeding ± SD duration of 8.20 ± 10.26 months, and body mass index (BMI) of 16.96 ± 3.03 kg/m(2) participated. Students had no CVD, liver or kidney diseases. Children were categorized in three groups of over 6 months breast-fed (>6 months group), less than 6 months breast-fed (≤6 months group), and formula group. The physician measured CRF calculating VO2 max; and reported the results as fitness or no fitness. The probable confounders were gender, BMI, fat-free mass, fat mass, mother's BMI, dietary Poly Unsaturated Fatty Acid (PUFA) and folate, beginning time of supplementary nutrition, physical activity, and birth weight. RESULTS: Breastfeeding more than 6 months was positively associated with CRF (p value < 0.001) before and after adjustment for confounders. The risk ratio (RR) of no CRF was 3.22 times more than >6 months group. VO2 max (ml/kg/min) was significantly the highest in >6 months group (p value = 0.001). CONCLUSION: Breastfeeding more than 6 months has positive effects on CRF, and the early nutrition may be a predictor for adolescence physical health.

Correlates of mental health service utilization in married women in tehran 2011.

OBJECTIVE: There are disparities in mental health services (MHS) utilization within and between populations and several factors are studied as its potential correlates. Identifying those correlates would help health policy makers to adjust service provision with characteristics of their community. To evaluate demographic, socioeconomic and system correlates of MHS utilization among married women from Tehran, Iran. METHODS: A household survey of 615 married women residents of 22 municipal districts of Tehran selected via a cluster sampling method. All subjects were asked about health services utilization during last one and 12 months as well as need and access for MHS, demographic and socioeconomic factors. Independent correlates of MHS use were determined with logistic regression analysis. RESULTS: Total 615 women, mean±SE age and duration of marital life of 42.6±0.9 and 22±0.8 years, respectively were selected, rate of MHS utilization during last one and 12 months were 5.2% and 10.1% respectively. 23.6% of women reported having mental illness and 19.3% and 17.9% had need for MHS and access to outpatient health services, respectively. Logistic regression models showed that need for MHS (OR:5.25, 95%CI:2.7-10.1), access to outpatient services (OR:2.17, 95%CI:1.04-4.52), smoking (OR:3.4, 95%CI:1.16-10.2) and crowding index (OR:0.69, 95%CI:0.48-0.99). CONCLUSIONS: Rate of MHS utilization in women are low considering the near to estimated rate of perceived illness. Bridging the gap between perceived illness and need for services, then providing better access to services in areas with higher crowding index and higher rates of smoking in residents should considered in any mental health promotion programs. DECLARATION OF INTEREST: None.

PRKN, DJ-1, and PINK1 screening identifies novel splice site mutation in PRKN and two novel DJ-1 mutations.

We present results of mutation screening of PRKN gene in 93 Iranian Parkinson's disease (PD) patients with average age at onset (AAO) of 42.2 years. The gene was screened by direct sequencing and by a semi-quantitative PCR protocol for detection of sequence rearrangements. Heterozygous rearrangements were tested by reverse transcription-polymerase chain reaction (RT-PCR). Nine different PRKN mutations were found. One of these, IVS9+1G>A, affects splicing and is novel. Two mutated PRKN alleles were observed in each of 6 patients whose average AAO was 25.7 years. Only 1 patient carried a single mutated allele and his AAO was 41 years. Among patients with AAO of <30 years, 31.3% had two mutated alleles, while only 2.6% with AAO of >30 years carried a PRKN mutation. Analysis of PRKN by RT-PCR led to identification of a novel exon expressed in leukocytes of control and PD individuals. The alternatively spliced transcript if translated would code a protein without a RING Finger 2 domain. Its functional relevance remains to be shown. DJ-I and PINK1 were also screened. Two novel DJ-1 mutations, c.91-2A>G affecting splicing and c.319G>C causing Ala107Pro, were observed among patients with AAO of <31 years, suggesting that PD in a high fraction (>12%) of this group of Iranian patients may be due to mutations in DJ-1. Mutations in PINK1 were not observed. Our results complement previous findings on LRRK2 mutations among Iranian PD patients.

Identification of four novel potentially Parkinson's disease associated LRRK2 variations among Iranian patients.

The results of mutation screening of 24 exons of LRRK2 in 60 Iranian Parkinson's Disease patients are presented. The Iranian cohort represents a novel population and was notably young (average age at onset of disease: 36.0 years). Fifty sequence variations were found, seventeen of which are novel. Variations considered possibly associated with disease were screened in available family members, 145 additional patients and 220 control individuals. It was surmised that four novel sequence variations (IVS49+178A>G, p.R1725Q, p.Q1823K, and p.D2175H) may be associated with PD status, albeit they may be very rare non-disease associated variations. The four variations were all observed in the heterozygous state in early onset cases. If one or more of the variations do indeed contribute to disease status, their penetrance is expected to be low.

A clinic-based screening of mutations in exons 31, 34, 35, 41, and 48 of LRRK2 in Iranian Parkinson's disease patients.

We present results of mutation screening of exons 31, 34, 35, 41, and 48 of LRRK2 in 205 Iranian Parkinson's disease patients. Sixteen percent of the cases were familial. Although age was not a factor in patient recruitment, the Iranian cohort was relatively young (average age at onset of disease: 48.9 years). A notably high male to female ratio (2.96:1) and earlier age at onset (by 2.9 years) in men were observed. A known disease-associated variation, c.C4321T causing R1441C, and IVS31 + 3A > G, a variation that may be associated, were observed. Therefore, disregarding IVS31 + 3A > G, disease status in at least 0.5% of our young cohort and in 3.5% of the familial cases was associated with a mutation in the five exons of LRRK2 screened. Interestingly, the variation causing p.G2019S was not observed.

Cross-sectional reference values for height, weight and body mass index of school children living in Tehran, Iran.

AIM: The aim of the study was to create reference values for weight, height and body mass index (BMI) of school children living in Tehran. METHOD AND SAMPLES: The study subjects consisted of 1,420 girls between 6 and 17 years of age and 1,515 boys between 6 and 15 years of age. Samples were collected by a multistage sampling method from schools in different areas of Tehran. All participants were established to be healthy and their height, weight and BMI evaluated. Reference standard values estimated by the LMS method using LMS Light software and 3rd, 5th, 10th, 25th, 50th, 75th, 90th, 97th and 85th (only for BMI) centiles were constructed and the results compared with US reference values. RESULTS: The centiles provided a good fit to the data. In boys, there were some significant differences of mean standard deviation scores (SDS) of height and BMI from zero, but there were no significant differences in weight. In girls, the mean SDS of height, weight and BMI were significantly lower than zero, especially for 7-9 years of age. Among 12-13-year-old girls, the mean SDS of height, weight and BMI came closer to zero, and the differences were not significant. Thereafter, although girls seemed to be shorter than US reference measures, their weight and BMI did not differ from reference values significantly. CONCLUSION: Our results for boys between 6 and 15 years are comparable with US reference values; however, the US reference values, especially for height, are not applicable for Iranian girls between 6 and 17 years.

Preliminary report of hepatitis B virus genotype prevalence in Iran.

AIM: To determine the prevalence of hepatitis B virus (HBV) genotypes in Iranian hepatitis B surface antigen (HBsAg) carriers, chronic hepatitis B and cirrhotic patients. METHODS: A total of 109 HBsAg-positive patients were included in this study. HBV genotypes were determined by using INNO-LiPA methodology which is based on the reverse hybridization principle. RESULTS: The distribution of patients with different stages of liver disease was as follows: 95(86.4%) chronic hepatitis, 11(10%) liver cirrhosis, and 3(2.7%) inactive carrier. Of the chronic hepatitis and liver cirrhosis patients, 26.4% were HBeAg-positive while 70% were HBeAg-negative. Genotype D was the only detected type found in all patients. CONCLUSION: Classifying HBV into genotypes has to be cost-effective and clinically relevant. Our study indicates that HBV genotype D prevails in the Mediterranean area, Near and Middle East, and South Asia. Continued efforts for understanding HBV genotype through international co-operation will reveal further virological differences of the genotypes and their clinical relevance.

Age of puberty in Iranian girls living in Tehran.

The aim of this study was to determine the age of appearance of secondary sexual characteristics in Iranian girls living in Tehran. A cross-sectional study was conducted between 2003 and 2004 on 1420 6-17-year-old females in different parts of Tehran. Data were collected on the basis of a multistage probability sampling. Secondary sexual characteristics were evaluated by inspection and palpation, and were recorded according to Tanner staging. The subjects were asked about the occurrence of menarche and the age of its onset. Generalized additive logistic modelling was used for the analysis of data. The median age (percentile 10-percentile 90) of Tanner 2 of breast development (B2) and Tanner 2 of pubic hair growth (P2) among 1136 girls was 9.74 years (8.23-11.94) and 10.49 years (8.86-12.17), respectively. The ages of the 2.5 percentile for B2 and P2 were 7.42 and 7.03 years, respectively, so the onset of puberty at < 7 years and 5 months is considered precocious in this population. The median age of menarche in 399 girls was 12.68 years (11.27-15.96).