Predictors of cardiovascular risk factors in Tehranian adolescents: Tehran Lipid and Glucose Study

INTRODUCTION: Cardiovascular disease (CVD) is one of the major health and social problems in Iran. The aim of this study is to determine the predictors of CVD risk factors in adolescents residing in district 13 of Tehran. METHODS: Dietary intake assessment was undertaken with two separate 24-hour recall interviews with adolescents aged 11-18 years, selected from among 15005 subjects who were participants of the Tehran Lipid and Glucose Study. After excluding the under- and over-reporters, 290 adolescents remained in the study. Data related to cigarette smoking was collected. Height and weight were assessed and body mass index (BMI) was calculated. Blood pressure was measured twice at intervals in a seated position. Serum cholesterol, triglycerides, and high-density lipoprotein (HDL) concentrations were measured in a blood sample after 12 hours of fasting, and low-density lipoprotein (LDL) was calculated. To determine the predictors of CVD risk factors stepwise linear regression was used. RESULTS: There were strong positive correlations between BMI and both systolic and diastolic blood pressure in girls: (beta = 1.8, p < 0.001; beta = 0.8, p < 0.001) and boys (beta =0.04, p < 0.001; beta = 0.05, p < 0.01). There was an inverse association between calcium intake and systolic (beta = -0.16, p < 0.05) and diastolic blood pressure in boys (beta = -0.36, p < 0.01), as well as inverse association between calcium intake and systolic (beta = -1.2, p < 0.05) and diastolic blood pressure (beta = -0.05, p < 0.05) and serum triglycerides (beta = -0.1, p < 0.01) in girls. Positive correlations were found between BMI and cholesterol in girls (beta = 0.2, p < 0.01) and boys (beta = 0.31, p < 0.01). CONCLUSION: Certain dietary and life style factors predict CVD risk factors in Tehranian adolescents.     

Abdominal obesity phenotypes and risk of kidney function decline: Tehran Lipid and Glucose Study

ObjectiveObesity and related health risk in different obesity phenotypes has always been a controversial subject. The present study was conducted with the aim of investigating the risk of kidney function decline (KFD) incidence in different abdominal obesity phenotypes.MethodsIn this prospective observational cohort study, 7002 individuals (56.1% female), aged ≥20 years, were followed for the incidence of KFD defined as 40% decline in eGFR. Abdominal obesity was defined based on waist circumference cut-offs ≥89/91 cm for men/women, respectively. Metabolic health was defined as ≤1 criterion of the metabolic syndrome criteria, according to the Joint Interim Statement (JIS) definition.ResultsAt baseline 4273 individuals (61.0%) were abdominally obese, among whom, 1188 (27.8%) belonged to the metabolically healthy abdominal obese (MHAO) phenotype. Totally, 251 incidences of KFD was indicated throughout the 12-year follow-up. After adjusting for the confounding variables, MHAO phenotype was not associated with increased risk of KFD in both males and females. Furthermore, results indicated that hazard ratios (HRs) for incidence of KFD did not increase in males with unhealthy obesity phenotypes. However, females with metabolically unhealthy abdominal obese (MUAO) phenotype had increased risk of KFD.ConclusionFindings of this study indicated that MHAO phenotype was not associated with KFD incidence, regardless of the participants gender. Furthermore, MUAO phenotype was associated with higher risk of KFD only in females. Further studies with longer follow up and larger sample size are needed to shed more light upon the regarded relationship and the influential role of gender.     

Dietary protein intake is associated with favorable cardiometabolic risk factors in adults: Tehran Lipid and Glucose Study

In this study, we investigated the hypothesis that dietary protein content and type are related to cardiometabolic risk factors including body mass index, waist circumference (WC), serum triglycerides, high-density lipoprotein cholesterol (HDL-C), serum fasting glucose, and blood pressure. This population-based study was conducted on 2537 subjects aged 19 to 70 years and selected from among participants of the Tehran Lipid and Glucose Study (2006-2008). Dietary data were collected using a validated semiquantitative food frequency questionnaire. Associations between intakes of total protein as well as the animal-to-plant (A/P) protein ratio and cardiometabolic risk factors were analyzed using multivariate linear regression models. Dietary protein intakes were 13.7% and 13.6% of energy, in men and women, respectively; the A/P protein ratio in women was significantly higher than in men (1.8±1.4 vs 1.4 ± 0.9). Body mass index was associated with total protein intake in men (β = 0.14, P = .01) and A/P protein ratio in women (β = 0.075, P = .01). Waist circumference was associated with total protein intake (β = −0.048, P = .03) and A/P protein ratio (β=0.031, P = .05) in women. Serum fasting glucose was associated with both total protein intake (β=0.061 and 0.11, P < .05) and the A/P proteinratio (β = −0.078 and −0.056, P < .05) in both men and women, respectively. Serum HDL-C was associated with total protein intake (β = 0.107 and 0.07, P < .05) in both men and women, whereas diastolic blood pressure in women was associated with total protein intake (β = −0.125, P = .01). In conclusion, higher dietary protein intake was associated with enhanced HDL-C levels, WC, and diastolic BP, and a higher ratio of A/P protein intake was related with lower serum fasting glucose andWC.     

Serum lipid levels in an Iranian adults population: Tehran Lipid and Glucose Study

Data from 6246 participants aged 20–64 years (2339 males and 3907 females) in the cross-sectional phase of Tehran Lipid and Glucose Study (February 1999–May 2000) were used to determine distribution of serum lipid levels after 12–14 hour overnight fast. Mean total cholesterol (TC) concentration was 210 mg/dl. TC was significantly greater in females than males, 213 and 206 mg/dl, respectively (p < 0.0001). Thirty-one percent of population had TC values between 200 and 239 and 24% had values of 240 mg/dl or greater. Mean low-density lipoprotein cholesterol (LDL-C) was 129 and 135 mg/dl in males and females, respectively (p < 0.0001). Twenty-seven percent had LDL-C values between 130 and 159 and 23% had values 160 mg/dl or greater. The mean triglycerides (TGs) values were 190 and 162 mg/dl for males and females, respectively (p < 0.0001). The mean high-density lipoprotein cholesterol (HDL-C) was 39 in males and 45 mg/dl in females (p < 0.0001). The results showed higher levels of TC, LDL-C and TGs and slightly lower HDL-C in Tehranian adults than other studies in the industrialized countries.     

Dietary total antioxidant capacity and incidence of chronic kidney disease in subjects with dysglycemia: Tehran Lipid and Glucose Study

Purpose

We aimed to investigate the association of dietary total antioxidant capacity (TAC) with incidence of CKD in subjects with dysglycemia.

Methods

We followed-up 1179 subjects aged ≥30 years with dysglycemia from the Tehran Lipid and Glucose Study (TLGS) for 3 years, who were initially free of CKD. Dietary intakes of TAC, vitamin C, vitamin E, and β-carotene were assessed by a food-frequency questionnaire at the baseline. Dietary TAC was estimated using the oxygen radical absorbance capacity method. Estimated glomerular filtration rate (eGFR) was calculated, using the Modification of Diet in Renal Disease Study equation and CKD was defined as eGFR <60 mL/min/1.73 m². Odds ratios (ORs) using multivariable logistic regression were reported for the association of incident CKD with dietary TAC.

Results

A total of 197 (16.7%) cases of incident CKD were recorded after 3 years of follow-up. After adjustment for age, sex, smoking, physical activity, body mass index, hypertension, and total energy intake, the top tertile of dietary TAC compared to the bottom was associated with 39% [95% confidence interval (CI) = 0.40–0.93] lower risk of incident CKD (P for trend = 0.025). Furthermore, the highest tertile of vitamin C intake compared to the lowest risk of incident CKD was decreased (OR 0.60; 95% CI 0.38–0.93, P trend 0.023). Intakes of vitamin E and β-carotene were not significantly associated with incident CKD risk.

Conclusion

Our findings suggest that diets high in TAC are associated with a lower risk of incident CKD among subjects with hyperglycemia after 3 years of follow-up.

     

Dietary quality-adherence to the dietary guidelines in Tehranian adolescents: Tehran Lipid and Glucose Study

The aim of this study was to determine the Healthy Eating Index (HEI) score and its relation take of nutrients and the number of servings from each food group consumed by adolescents residing in district 13 of Tehran. This study, conducted within the framework of Tehran Lipid and Glucose Study (TLGS), was a part of a dietary intake assessment carried out in 443 families, including 465 adolescents, aged 10-18 years, according to the Food Guide Pyramid and dietary guidelines on individuals residing in district 13 of Tehran. In this study, dietary intake was assessed with two-day 24-hour recalls. HEI was calculated based on nine components. The score range of each component was 0 to 10, the sum score of this index therefore being 90. The HEI score was categorized into three groups: less than 45 (poor diet), between 45-72 (needs improvement) and more than 72 (good diet). The mean score of HEI was 64.9 +/- 9.6 in boys and 64.8 +/- 9.4 in girls. The results showed that the number of servings of food groups in those with good diet was significantly higher than the two other groups (p < 0.05). In contrast the percent of saturated fat intake and cholesterol consumption in those with HEI > or = 72 was lower than the other groups (p < 0.05). The approximate number of food items consumed and the total nutrient intake by adolescents with HEI score > or = 72 was significantly higher than the others (p < 0.05). There was a significant positive correlation between the number of servings of grains group (r = 0.1), vegetables (r = 0.4), fruits (r = 0.4), dairy (r = 0.3), meat (r = 0.1), and HEI (p < 0.001). There was a significant negative correlation between fat intake (r = -0.2, p < 0.001), percent of saturated fatty acids (r = -0.2, p < 0.05), cholesterol consumption (r = -0.4, p < 0.05), and the ratio of polyunsaturated fatty acids/saturated fatty acids (P/S) in diet (r = 0.2, p < 0.05), and HEI score. Seventy-four, 23, and 3% of diets were categorized into needs improvement, good, and poor, respectively. In conclusion, the diets of most Tehranian adolescents need improvement, demonstrating the need for nutrition education in this age group.     

Dietary Quality among Tehranian Adults in Relation to Lipid Profile: Findings from the Tehran Lipid and Glucose Study

The prevalence of dyslipidaemia has been increasing in developing countries that are undergoing nutrition transition. However, the association of diet quality and lipid profile has not been well-understood in these countries. The aim of the current study was to compare the ability of three diet quality indices—the Mediterranean diet scale (MDS), healthy eating index-2005 (HEI-2005), and diet quality index-international (DQI-I) in relation to changes in lipid profile between baseline and 6.7 years of follow-up. Baseline data from two 24-hour dietary recalls provided by 469 adults with mean age of 38.7±12.3 years, who were participants of the Tehran Lipid and Glucose Study, were analyzed to describe dietary intakes. Data on anthropometry, sociodemography, physical activity, and other lifestyle variables were recorded, and a comparison of baseline and follow-up data revealed changes in the concentrations of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C). A general linear model was used in assessing changes in lipid profile depending on adherence to diet quality indices at baseline, after adjustment for age, smoking status, waist-circumference, body mass index, physical activity, and energy intake. A significant interaction was observed between scores and sex, and upon stratification, males in the highest quartile score of the HEI-2005 had significantly lower TG changes than those in the lowest quartile, after adjusting for confounders (-8.8 vs 2.9, p=0.038). No association was apparent in females (-0.2 vs 11.2, p=0.297). In addition, a positive association was found between DQI-I and HDL-C (Q1=0.6 vs Q4=-2.0, p=0.044) in males. In both sexes, all these indices were weakly associated with TC while none was associated with LDL-C. It is concluded: adherence to the HEI-2005 recommendations was weakly associated with reduced TG concentration in an urban Iranian adult population. The MDS and DQI-I were not related to change in lipid profile.Key words: Diet quality index-international, Healthy eating index-2005, Lipid profile, Mediterranean diet scale     

Adult family members and their resemblance of coronary heart disease risk factors: The Cardiovascular Disease Study in Finnmark

Coronary heart disease tends to run in families, and the familial resemblance of major risk factors for the disease was examined among various types of adult family members. Family units were assembled from a total of 4,738 men and women who took part in a cross sectional health survey in four Norwegian municipalities where all inhabitants between 20 and 52 years of age were invited. After adjusting for age and other confounders, correlation coefficients were derived as a measure of the degree of resemblance. Viewed across all types of investigated familial relationships, similarity was found to be stronger for total cholesterol than for high-density lipoprotein cholesterol and triglycerides, and also stronger for systolic than for diastolic blood pressure. Between husbands and wives (3,060 subjects), correlations were small (between 0.02 and 0.06), except for 0.11 for total cholesterol. Lipid and blood pressure correlations ranged from 0.13 to 0.27 for parents and their offspring (471 subjects, p < 0.05) and from 0.11 to 0.22 among siblings (2,166 subjects, p < 0.01). Sibling correlations were consistent across age groups. Furthermore, reports from each individual on daily smoking (yes or no) revealed that husbands and wives had similar habits in 63.5% of all marriages as compared with the expected 49.4% had no smoking similarity at all been present. Smoking concordance was also demonstrated among siblings (p < 0.01). The persistent pattern of lipid and blood pressure aggregation among genetically related individuals from 20 to 52 years of age and the much weaker such similarity between husbands and wives, point towards genes or commonly shared environment at early ages as a major reason why coronary heart disease runs in families.     

Combined effects of saturated fat and cholesterol intakes on serum lipids: Tehran Lipid and Glucose Study

ObjectiveThis study investigated the combined effect of saturated fat and cholesterol intake on serum lipids among Tehranian adults.MethodsIn 443 subjects ≥18 y, dietary intake was assessed. Height and weight were measured and body mass index was calculated. Serum cholesterol, triacylglycerol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol levels were calculated. Cholesterol intakes ≥300 mg/d and saturated fat intakes ≥7% of total energy were defined as high intakes. Individuals were categorized into four groups based on cholesterol and saturated fat intakes.ResultsSubjects' mean age was 40.1 ± 14.6 y; those in whom cholesterol and saturated fat intake was normal had significantly less energy and fat intake than those with high cholesterol and saturated fat intakes (P < 0.01). Saturated fat intake had a significant effect on serum total and HDL-C levels. Subjects with a normal saturated fat intake had significantly less serum total and HDL-C than those who had high saturated fat intake (P < 0.01 and P < 0.05, respectively). Adjusting for age, sex, and body mass index, the main effect of cholesterol intake on HDL-C was significant (P = 0.05). Mean serum HDL-C was lower in subjects who had normal cholesterol intake than in those with high cholesterol intake.ConclusionThese results show that cholesterol and saturated fat intakes have no combined effect on serum low-density lipoprotein cholesterol level, whereas cholesterol intake per se affects serum HDL-C level.     

Evaluation of waist circumference to predict cardiova scular risk factors in an overweight Tehranian population: findings from Tehran Lipid and Glucose Study

This study was conducted to evaluate the waist circumference (WC) cut-off points to predict cardiovascular risk factors in the overweight Tehranian population. Anthropometric measures, blood pressure, and biochemical analyses were evaluated for the 15,005 participants of the Tehran Lipid and Glucose Study. Three thousand sixty-five subjects aged 18-74 years with a body mass index of 25-29.9 were enrolled in this study. Abdominal obesity was defined as WC > or =102 cm for men and > or =88 cm for women. Sensitivity of WC > or =102 cm to detect various cardiovascular risk factors for men aged 35-54 years was between 5% and 14%, and for men aged 55-74 years, was between 12% and 19%. The specificity of this cut-off point was between 93% and 98% and between 86% and 96% for corresponding age-categories, respectively. WC > or =88 cm had a sensitivity of between 28% and 41 % for identifying cardiovascular risk factors in women aged 18-34 years. Sensitivity tended to increase with age and specificity tended to decrease with age in both genders. These cut-off points had the highest positive predictive value for the more prevalent risk factors in both genders. The negative predictive values were different for various risk factors among age groups. The classic cut-off points of WC failed to provide adequate evidence for the use of WC in detecting cardiovascular risk factors. Further studies should be conducted to determine optimal WC cut-off points for Iranians.     

Adult socioeconomic position and the association between height and coronary heart disease mortality: findings from 33 years of follow-up in the Whitehall Study

In the Whitehall Study, which followed 17,139 male civil servants over 33 years, the association between tall stature and coronary heart disease (CHD) mortality differed between employment grades. In men without CHD at study entry, the hazard ratio per 15-cm increase in height was 0.77 (95% confidence interval [CI]=0.69, 0.85; P<0.001) for the highest grades, but 0.84 (95% CI=0.69, 1.03; P=.10) for middle and 0.95 (95% CI=0.75, 1.20; P=.65) for low grades, suggesting that childhood and adult social conditions may interact in their influence on coronary risk.     

Metacarpal cortical area and risk of coronary heart disease: the Framingham Study

The objective of this study was to determine the relation between bone mass and the incidence of coronary heart disease in women and men. Participants included 2,059 cohort members of the Framingham Study (1,236 women and 823 men aged 47-80 years) who underwent posteroanterior hand radiography and were free from cardiovascular disease at baseline (1967-1970) and who were then followed for 30 years through the end of 1997 for the incidence of coronary heart disease. The incidence of coronary heart disease decreased from 15.65/1,000 person-years among women in the lowest metacarpal cortical area quartile to 11.76/1,000 person-years among women in the highest quartile (p(trend) = 0.03), and the inverse relation persisted after adjustment for confounders (highest vs. lowest quartile of metacarpal cortical area: hazard ratio = 0.73, 95% confidence interval: 0.53, 1.00; p(trend) = 0.03). In contrast, no association was present in men (highest vs. lowest quartile of metacarpal cortical area: hazard ratio = 1.14, 95% confidence interval: 0.84, 1.56; p(trend) = 0.55).     

Multivariate risk estimation for coronary heart disease: the Busselton Health Study

Coronary heart disease (CHD) is a multifactorial disease and CHD risk should be estimated by assessing all cardiovascular risk factors simultaneously. Simply adding up the number of factors with 'at risk' values fails to identify high-risk subjects with multiple risk factors at moderately elevated values. A more efficient approach is to use a quantitative multivariate risk score. A number of overseas studies have produced CHD risk scoring systems for men. There are few risk scores developed for women and no CHD risk scores have been developed from Australian data. This study used data on CHD risk factors and morbidity/mortality follow-up for the 1978 Busselton Health Survey participants to provide age-specific estimates of absolute risk of CHD hospitalisation or death, and to develop multivariate CHD risk scoring systems for men and women. The scores are based on age, blood pressure, anti-hypertensive medication, total and HDL cholesterol, smoking, diabetes, left ventricular hypertrophy and previous history of CHD. The generalisability and applicability of these risk estimation systems to Australian populations in the late 1990s is discussed.     

Dietary fat intake and risk of coronary heart disease: the Strong Heart Study

BACKGROUND: The results of previous studies on the association between dietary fat intake and coronary heart disease (CHD) incidence are inconsistent. OBJECTIVE: The aim of this study was to examine the association between dietary fat intake and CHD incidence in American Indians in the Strong Heart Study. DESIGN: A total of 2938 participants aged 47-79 y and free of CHD at the second examination (1993-1995) were examined and followed for CHD, nonfatal CHD, and fatal CHD events to 31 December 2002. Dietary intake was assessed by using a 24-h diet recall and was calculated as percentages of energy. RESULTS: Participants were followed for a mean (+/-SD) of 7.2 +/- 2.3 y. During follow-up, 436 incident CHD cases (298 nonfatal CHD and 138 fatal CHD events) were ascertained. Participants aged 47-59 y in the highest quartile of intake of total fat, saturated fatty acids, or monounsaturated fatty acids had higher CHD mortality than did those in the lowest quartile [hazard ratio (95% CI): 3.57 (1.21, 10.49), 5.17 (1.64, 16.36), and 3.43 (1.17, 10.04), respectively] after confounders were controlled for. These associations were not observed for those aged 60-79 y. CONCLUSIONS: Total fat, saturated fatty acid, and monounsaturated fatty acid intake were strong predictors of CHD mortality in American Indians aged 47-59 y, independent of other established CHD risk factors. It may be prudent for American Indians to reduce their fat intake early in life to reduce the risk of dying from CHD.