Ethnicity and the association between anthropometric indices of obesity and cardiovascular risk in women: a cross-sectional study

Prediction of cardiovascular disease risk by serum zinc and copper concentrations and anthropometric measurements

INTRODUCTION

We aimed to investigate the association between cardiovascular disease (CVD) and various anthropometric indices, as well as the serum levels of copper (Cu) and zinc (Zn), copper-zinc ratio (Cu/Zn ratio) and zinc-copper ratio (Zn/Cu ratio), in a large population sample from northeastern Iranian.

METHOD

9704 individuals aged 35 to 65 were enrolled in the first phase of the study. After a 10-year follow-up, 7560 participants were enrolled into the second phase. The variables used in this study included demographic characteristics, such as gender and age; biochemical parameters including: serum Zn, Cu, Cu/Zn ratio, and Zn/Cu ratio; anthropometric parameters including: waist circumference (WC), body mass index (BMI), and waist-to-hip ratio (WHR). The relationship between the aforementioned indices and CVD was examined using decision tree (DT) and logistic regression (LR) models.

RESULTS

A total of 837 individuals were diagnosed with CVD among the 7560 participants. LR analysis showed that BMI, age, WH zinc-copper ratio (Zn/Cu ratio), and serum Zn/Cu ratio were significantly associated the development of CVD in men, and WHR, age, BMI, serum Cu, and Cu/Zn ratio in women. DT analysis showed that, age was the most important predictor of CVD in both genders. 71% of women, older than 49 years, with a WHR≥ 0.89, serum Cu< 75 (µg/dl), BMI≥ 22.93 (kg/m2), and serum Cu≥ 14 (µg/dl), had the highest risk of CVD. In men, among those who were ≥ 53 years, with a WHR≥ 0.98, serum Zn/Cu ratio< 1.69, and BMI≥ 22.30, had the highest risk of CVD.

CONCLUSION

Among Iranian adult population, BMI, age, and WHR were one of the predictors of CVD for both genders. The Zn/Cu ratio was CVD predictor for men while Cu/Zn ratio was CVD predictor for women.

Development of Data Mining Algorithms for Identifying the Best Anthropometric Predictors for Cardiovascular Disease: MASHAD Cohort Study

INTRODUCTION

Many studies have been published to assess the best anthropometric measurements associated with cardiovascular diseases (CVDs), but controversies still exist.

AIM

Investigating the association between CVDs and anthropometric measurements among Iranian adults.

METHODS

For a total population of 9354 aged 35 to 65, a prospective study was designed. Anthropometric measurements including ABSI (A Body Shape Index), Body Adiposity Index (BAI), Body Mass Index (BMI), Waist to Height Ratio (WHtR), Body Round Index (BRI), HC (Hip Circumference), Demispan, Mid-arm circumference (MAC), Waist-to-hip (WH) and Waist Circumference (WC) were completed. The association between these parameters and CVDs were assessed through logistic regression (LR) and decision tree (DT) models.

RESULTS

During the 6-year follow-up, 4596 individuals (49%) developed CVDs. According to the LR, age, BAI, BMI, Demispan, and BRI, in male and age, WC, BMI, and BAI in female had a significant association with CVDs (p-value < 0.03). Age and BRI for male and age and BMI for female represent the most appropriate estimates for CVDs (OR: 1.07, (95% CI: 1.06, 1.08), 1.36 (1.22, 1.51), 1.14 (1.13, 1.15), and 1.05 (1.02, 1.07), respectively). In the DT for male, those with BRI ≥ 3.87, age ≥ 46 years, and BMI ≥ 35.97 had the highest risk to develop CVDs (90%). Also, in the DT for female, those with age ≥ 54 years and WC ≥ 84 had the highest risk to develop CVDs (71%).

CONCLUSION

BRI and age in male and age and BMI in female had the greatest association with CVDs. Also, BRI and BMI was the strongest indices for this prediction.

Predictive ability of six obesity measures to identify 7-year fatal and non-fatal cardiovascular events: A population-based cohort study

Background

Globally, most people die from cardiovascular diseases. We aimed to compare predictive ability of six obesity indices, including body mass index, waist circumference, waist-to-hip ratio, waist-to-height ratio, conicity index, and abdominal volume index, to identify people at risk of fatal and non-fatal cardiovascular events, in a cohort study.

Methods

We studied 5147 participants in a baseline population-based cohort study conducted in northern Iran. The obesity measures were calculated in enrollment phase (2009–2010), and the cardiovascular events were recorded during a 7-year follow-up phase (2010–2017). Receiver operating characteristic (ROC) analyses and Cox hazard regression models were applied, considering the obesity measures as predictors, and the 7-year cardiovascular events as outcomes. Multiple Cox models were adjusted by age, prior history of cardiovascular diseases, chronic kidney diseases, insulin resistance, diabetes mellitus, dyslipidemia, hypertension, and smoking status.

Results

Conicity index showed the highest performance in predicting 7-year fatal and non-fatal cardiovascular events with areas under the ROC curve of 0.77 [95% confidence interval: 0.71–0.82], and 0.63 [0.59–0.68] in men, and 0.80 [0.74–0.87], and 0.65 [0.60–0.71] in women, respectively. In multiple Cox models, the obesity measures had no significant associations with cardiovascular events in women. In men, only waist-to-height ratio was independently associated with 7-year non-fatal cardiovascular events (hazard ratio: 1.19 [95% confidence interval: 1.01–1.38]).

Conclusions

Although waist-to-height ratio had an independent association with 7-year non-fatal cardiovascular events in men, conicity index showed the best ability to predict 7-year fatal and non-fatal cardiovascular events in our study.

Anthropometric indices and cut-off points for screening of metabolic syndrome among South African taxi drivers

Background

Detecting the early onset of metabolic syndrome (MetS) allows for quick intervention which may slow progression to a variety of health consequences, hence, determining the best measurement to detect MetS is essential.

Aim

This research aimed at examining the MetS predictive power of anthropometric indices, such as body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), body shape index (ABSI), body roundness index (BRI), percentage body fat (%BF), conicity index (CI), and Clínica Universidad de Navarra-body adiposity estimator (CUN-BAE) to determine the cut-off points to identify male South African taxi drivers with MetS.

Method

A cross-sectional study was conducted among 185 male taxi drivers. Their weight, height, WC, blood lipid profile were measured. International Diabetes Federation (IDF) definition was used to define MetS. Receiver Operating Characteristic (ROC) curves were used to compare the predictive ability of Anthropometric indices to detect MetS.

Results

The mean age of the participants was 39.84 years. Overall, 41.6% (N = 77) of the participants presented with MetS. The mean values for BMI, WC, WHtR, %BF, BRI, CUN-BAE, ABSI and CI were 28.60 ± 6.20 kg/m², 99.13 ± 17.59 cm, 0.58 ± 0.10, 27.28 ± 8.28%, 5.09 ± 2.33, 27.78 ± 8.34, 0.08 ± 0.01 and 1.70 ± 0.19, respectively. The mean values for these indices were significantly (p < 0.001) higher in participants with MetS. The highest area under the curve (AUC) outcomes for screening MetS were for the %BF and CUN-BAE, followed by the BMI and WHtR, and lastly the BRI. All these anthropometric indices had outstanding discriminatory powers for predicting MetS with AUCs and sensitivity values above 80%. The BMI, WHtR, %BF, BRI, and CUN-BAE, had cut-off points for detection of metS in South African men at 28.25 kg/m², 0.55, 25.29%, 4.55, and 27.10, respectively. Based on the logistic regression models abnormal BMI, WHtR, %BF, BRI, CUN-BAE, TG, FBG, systolic BP, diastolic BP and WC showed increased risk of MetS.

Conclusion

While the %BF, CUN-BAE, BMI, WC, WHtR, BRI, CI and CUN-BAE could predict MetS among South African male taxi drivers, these indices were less effective in predicting the individual MetS risk factors such as TG, BP, and FBG.

Development of the Anthropometric Grouping Index for the Eastern Caribbean Population Using the Eastern Caribbean Health Outcomes Research Network (ECHORN) Cohort Study Data

Improving public health initiative requires an accurate anthropometric index that is better suited to a specific community. In this study, the anthropometric grouping index is proposed as a more efficient and discriminatory alternative to the popular BMI for the Eastern Caribbean population. A completely distribution-free cluster analysis was performed to obtain the 11 categories, leading to AGI-11. Further, we studied these groups using novel non-parametric clustering summaries. Finally, two generalized linear mixed models were fitted to assess the association between elevated blood sugar, AGI-11 and BMI. Our results showed that AGI-11 tends to be more sensitive in predicting levels of elevated blood sugar compared to BMI. For instance, individuals identified as obese III according to BMI are (POR: 2.57; 95% CI: (1.68, 3.74)) more likely to have elevated blood sugar levels, while, according to AGI, individuals with similar characteristics are (POR: 3.73; 95% CI: (2.02, 6.86)) more likely to have elevated blood sugar levels. In conclusion, the findings of the current study suggest that AGI-11 could be used as a predictor of high blood sugar levels in this population group. Overall, higher values of anthropometric measures correlated with a higher likelihood of high blood sugar levels after adjusting by sex, age, and family history of diabetes.

A Comparison of Statin Treatment Algorithms Based on the ACC/AHA and Philippine Guidelines for Primary Prevention of Dyslipidemia in Statin-Naive Filipino Patients

Objectives

This cross-sectional study evaluates the degree of agreement between the 2018 American College of Cardiology/American Heart Association (ACC/AHA2018) and 2020 Philippine Guideline (PG2020) treatment algorithms for the primary prevention of dyslipidemia among Filipinos.

Methodology

This review included 159 charts of statin-naive Filipinos who are 45-79 years old. Using risk profile and lipid measurements, statin treatment recommendation was determined through the PG2020 algorithm and ACC/AHA-ASCVD Risk Estimator Plus web application. The degree of agreement was measured by Cohen's kappa statistic with the two algorithms as independent raters.

Results

A total of 159 patients were included in the final analysis. There was a slight agreement with a kappa coefficient of 0.209 or 4.4% (95% CI 0.078-0.340, p=0.003). Statin treatment was recommended in 69 out of 159 patients (43.4%) by the PG2020 overlapping with ACC/AHA2018 in 56 cases (81.2%). On the other hand, 109 cases (68.6%) were recommended for statin treatment by ACC/AHA2018 overlapping with PG2020 in only 51.4%.

Conclusions

The low degree of agreement between the two treatment algorithms highlights the key demographic and ethnic variations in dyslipidemia management necessitating outcome-based studies to translate these differences. Overestimation of ASCVD risk calculation in the ACC/AHA2018 and consideration of important, unique risk factors among Filipinos favors the applicability of the Philippine guideline.

Comparing the predictive ability of the Edmonton Obesity Staging System with the body mass index for use of health services and pharmacotherapies in Australian adults: A nationally representative cross-sectional study

We assessed the value of the Edmonton Obesity Staging System (EOSS) compared with the body mass index (BMI) for determining associations with use of health services and pharmacotherapies in a nationally representative sample of participants in the 2011-2013 Australian Health Survey. A subsample of participants aged 18 years or over, with at least overweight (BMI ≥ 25 kg/m² ) or central obesity (waist measurement of ≥102 cm for men; ≥88 cm for women), and who had provided physical measurements (n = 9730) were selected for analysis. For statistical significance of each predictor, we used logistic regression for model comparisons with the BMI and EOSS separately, and adjusted for covariates. For relative explanatory ability, we used the Nagelkerke pseudo R² , receiver operating characteristic curve, and area under curve statistic. The EOSS was significantly better than the BMI for predicting polypharmacy and most of the health service use variables. Conversely, the BMI was significantly better than the EOSS for predicting having discussed lifestyle changes relevant to weight loss with the primary care physician. Clinicians, health care professionals, consumers, and policy makers should consider the EOSS a more accurate predictor of polypharmacy and health service use than the BMI in adults with overweight or obesity.

Comparison of anthropometric indices as predictors of the risk factors for cardiovascular disease in Iran: The PERSIAN Guilan Cohort Study

OBJECTIVE

This study was conducted to assess the prevalence of central and general obesity and compare nine anthropometric indices as predictors of the risk factors for cardiovascular disease (CVD) in Iranian adults.

METHODS

A total of 10,520 adults between ages 35 and 70 years old who were referred to the PERSIAN Guilan Cohort Study were included in this study. Anthropometric indices, including body mass index (BMI), waist circumference (WC), waist to height ratio (WHtR), waist to hip ratio (WHR), conicity index, hip circumference (HC), waist to hip to height ratio (WHHR), body adiposity index, and a body shape index (ABSI), were measured using the standard methods. The risk factors for CVD (diabetes mellitus, hypertension, and out of range lipid profiles) were defined by laboratory tests and medical history. The odds ratio of the risk factors based on a unit increase in anthropometric indices was examined by an adjusted logistic model.

RESULTS

The mean of all anthropometric indices was higher in women than in men (p<0.01). After adjusting for confounders, the risk of diabetes mellitus, hypertension, and hypertriglyceridemia increased with an increase in all anthropometric indices. The highest risk of diabetes mellitus and hypertriglyceridemia was found in higher WHHR. The highest risk of low high density lipoprotein cholesterol (HDL C) and high low density lipoprotein cholesterol (LDL C) was found in an increase in the WHR and ABSI, respectively.

CONCLUSION

Our findings emphasize higher levels of general and central obesity in adults in the north of Iran. The WHHR and WHtR seem to be more valuable indices than BMI and WC for predicting distinct risk factors for CVD. However, the WHR was the strongest index for the prediction of high LDL C/HDL C ratio.

Indicators of Abdominal Adiposity and Carotid Intima-Media Thickness: Results from the Longitudinal Study of Adult Health (ELSA-Brazil)

BACKGROUND

Abdominal adiposity is a risk factor for cardiovascular disease.

OBJECTIVE

To determine the magnitude of the association between abdominal adiposity, according to five different indicators, and the carotid intima-media thickness (CIMT).

METHODS

Data from 8,449 participants aged 35 to 74 years from the ELSA-Brazil study were used. The effect of waist circumference (WC), waist-to-hip ratio (WHR), conicity index (C index), lipid accumulation product (LAP) and visceral adiposity index (VAI) on CIMT were evaluated. Data were stratified by gender and analyzed using multivariate linear and logistic regressions. A significance level of 5% was considered.

RESULTS

Participants with CIMT > P75 showed a higher frequency of abdominal adiposity (men >72% and women >66%) compared to those with CIMT < P75. Abdominal adiposity was associated with the mean CIMT, mainly through WC in men (0.04; 95%CI: 0.033; 0.058). The abdominal adiposity identified by the WC, WHR, LAP, and VAI indicators in women showed an effect of 0.02 mm on the CIMT (WC: 0.025, 95%CI: 0.016, 0.035; WHR: 0.026, 95%CI: 0.016, 0.035; LAP: 0.024, 95%CI: 0.014; 0.034; VAI: 0.020, 95%CI: 0.010, 0.031). In the multiple logistic regression, the abdominal adiposity diagnosed by WC showed an important effect on the CIMT in both genders (men: OR = 1.47, 95%CI: 1.22-1.77, women: OR = 1.38; 95%CI: 1.17-1.64).

CONCLUSION

Abdominal adiposity, identified through WC, WHR, LAP, and VAI, was associated with CIMT in both genders, mainly for the traditional anthropometric indicator, WC.

Comparison of abdominal obesity measures in predicting of 10-year cardiovascular risk in an Iranian adult population using ACC/AHA risk model: A population based cross sectional study

BACKGROUND

Several abdominal obesity measures have been used for prediction of 10-year cardiovascular disease (CVD) risk but the superiority of these measures remains controversial. The objective of this study was to assess the predictive ability of abdominal obesity measures for risk of CVD events in an Iranian adult population.

METHODS

We analyzed the data of population based cross-section study of 567 representative samples of adult population aged 40-70 years in Babol, the north of Iran. The demographic data, the anthropometric measures, lipid profile and cardiometabolic risk factors were measured with standard methods. Waist to hip ratio (WHR), waist to height ratio (WHtR), conicity index(CI), abdominal volume index (AVI) and body mass index(BMI)were calculated. The individual 10-year CVD risk was estimated based on ACC/AHA model. ROC analysis was performed to assess the diagnostic ability of different abdominal obesity measures and body mass index (BMI) in predicting of high risk of CVD events.

RESULTS

About 42.5% of men and 15% of women had at least 10% risk of 10-year cardiovascular events and 21.1% of men and 3.0% of women had ≥20% risk. Except WHR for men, all abdominal obesity measures significant predictors for ≥10% risk CVD risk in both sexes but not BMI. The greater ability of CVD risk prediction was observed by WHtR and CI in both sexes with higher AUC in females compared with men for ≥10% risk.

CONCLUSION

WHtR and CI are superior indexes in predicting of high risk of CVD events in both sexes.

Global genetic differentiation of complex traits shaped by natural selection in humans

There are mean differences in complex traits among global human populations. We hypothesize that part of the phenotypic differentiation is due to natural selection. To address this hypothesis, we assess the differentiation in allele frequencies of trait-associated SNPs among African, Eastern Asian, and European populations for ten complex traits using data of large sample size (up to ~405,000). We show that SNPs associated with height ([Formula: see text]), waist-to-hip ratio ([Formula: see text]), and schizophrenia ([Formula: see text]) are significantly more differentiated among populations than matched "control" SNPs, suggesting that these trait-associated SNPs have undergone natural selection. We further find that SNPs associated with height ([Formula: see text]) and schizophrenia ([Formula: see text]) show significantly higher variance in linkage disequilibrium (LD) scores across populations than control SNPs. Our results support the hypothesis that natural selection has shaped the genetic differentiation of complex traits, such as height and schizophrenia, among worldwide populations.

The SRGAP2 SNPs, their haplotypes and G × E interactions on serum lipid traits

Maonan nationality is a relatively conservative and isolated minority in China. Little is known about the association of the Slit-Robo Rho GTPase activating protein 2 gene (SRGAP2) single nucleotide polymorphisms (SNPs) and serum lipid levels in the Chinese populations. This study was performed to clarify the association of the SRGAP2 rs2483058 and rs2580520 SNPs and their haplotypes with serum lipid traits in the Maonan and Han populations. Genotyping of the 2 SNPs was performed in 2444 unrelated subjects (Han, 1210 and Maonan, 1234) by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing. The allelic (rs2483058) and genotypic (rs2483058 and rs2580520) frequencies were different between the two ethnic groups. Four haplotypes were identified in our populations, and the rs2483058G-rs2580520C haplotype was the commonest one. The rs2483058C-rs2580520G haplotype was associated with an increased risk of dyslipidemia, and showed consistent association with serum total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), apolipoprotein (Apo) A1 levels, and the ApoA1/ApoB ratio. These results indicated that the SRGAP2 SNPs and their haplotypes were associated with serum lipid levels. Their haplotypes can explain much more serum lipid variation than any single SNP alone, especially for serum TC, HDL-C and ApoA1 levels.

The Definition and Prevalence of Obesity and Metabolic Syndrome

Increase in prevalence of obesity has become a worldwide major health problem in adults, as well as among children and adolescents. Furthermore, total adiposity and truncal subcutaneous fat accumulation during adolescence are positively and independently associated with atherosclerosis at adult ages. Centrally accumulation of body fat is associated with insulin resistance, whereas distribution of body fat in a peripheral pattern is metabolically less important. Obesity is associated with a large decrease in life expectancy. The effect of extreme obesity on mortality is greater among younger than older adults. In this respect, obesity is also associated with increased risk of several cancer types. However, up to 30% of obese patients are metabolically healthy with insulin sensitivity similar to healthy normal weight individuals, lower visceral fat content, and lower intima media thickness of the carotid artery than the majority of metabolically "unhealthy" obese patients.Abdominal obesity is the most frequently observed component of metabolic syndrome. The metabolic syndrome; clustering of abdominal obesity, dyslipidemia, hyperglycemia and hypertension, is a major public health challenge. The average prevalence of metabolic syndrome is 31%, and is associated with a two-fold increase in the risk of coronary heart disease, cerebrovascular disease, and a 1.5-fold increase in the risk of all-cause mortality.

Association between the MVK and MMAB polymorphisms and serum lipid levels

Maonan ethnic group is a relatively conservative and isolated minority in China. Little is known about the association of the mevalonate kinase (MVK), methylmalonic aciduria (cobalamin deficiency) cblB type (MMAB) single nucleotide polymorphisms (SNPs) and serum lipid levels. This study aimed to determine the association between four SNPs in the MVK/MMAB and serum lipid levels. Genotyping of the rs3759387, rs877710, rs7134594 and rs9593 SNPs was performed in 1264 Maonan subjects and 1251 Han participants. Allele and genotype frequencies of the selected SNPs were different between the two populations (P < 0.05-0.001). Four SNPs were associated with high-density lipoprotein cholesterol (HDL-C) in the both ethnic groups (P < 0.0125-0.001); and one SNP with apolipoprotein (Apo) A1 (rs7134594) in Han Chinese (P <0.0125). Strong linkage disequilibria were noted among the SNPs (D'=0.63-0.96; r² =0.13-0.88). The commonest haplotype was C-C-C-T (> 50%). The frequencies of C-C-C-T, C-G-T-A, A-G-T-A, C-G-C-T, and A-C-T-A were different between the two populations (P <0.001). The associations between haplotypes and dyslipidemia were different in the Han and/or Maonan population (P < 0.05-0.001), haplotypes could explain much more serum lipid variation than any single SNP alone especially for HDL-C. Differences in lipid profiles between the two populations might partially attribute to these SNPs and their haplotypes.

The association between various indices of obesity and severity of atherosclerosis in adults in the north of Iran

Recent observational studies have reported controversial results for the association between different anthropometric indices of obesity and severity of atherosclerosis. The aim of the current study is to determine the associations between anthropometric indices with severity of atherosclerosis in adult population in north of Iran.The cross-sectional study was performed on 610 participants, who were admitted to a hospital for elective angiographyin Rasht, Iran, Anthropometric indices, including waist circumference (WC), waist-to-height ratio (WHtR), conicity index (CI), body mass index (BMI), and hematological factors, were measured using the standard methods. According to angiography reports, severity of atherosclerosis was determined.Sixty-two percent of participants had moderate to severe atherosclerosis. According to BMI, 44% were overweight and 25.8% were obese. Based on WHtR and WC, 90%, and 57% were obese, respectively. The prevalence of moderate to severe atherosclerosis in centrally obese women was significantly higher than in centrally nonobese women (52% vs 28% P = 0.02). According to multivariate adjustment analysis, age, sex, systolic blood pressure, hemoglobin A1c, uric acid, and triglyceride were independently associated with severity of atherosclerosis. BMI, WC, CI, and WHtR had no significant association with severity of atherosclerosis.Our findings showed that anthropometric indices reflective of general and abdominal obesity were not independently related to the severity of atherosclerosis in adults, in northern Iran.

Traditional Breast Cancer Risk Factors in Filipina Americans Compared with Chinese and Japanese Americans in Los Angeles County

BACKGROUND

Filipina Americans have one of the highest breast cancer incidence rates among Asian Americans for poorly understood reasons.

METHODS

Breast cancer risk factors were investigated in a population-based study of Filipina (790 cases, 587 controls), Japanese (543 cases, 510 controls), and Chinese (913 cases, 904 controls) Americans. Cases were identified by the Los Angeles County Cancer Surveillance Program, and controls were matched to cases on age, ethnicity, and neighborhood. Multivariable conditional logistic regression was performed by Asian ethnicity.

RESULTS

In Filipina, Chinese, and Japanese Americans, breast cancer risk decreased significantly with increasing parity (all Ptrend < 0.0001). Breast cancer risk increased with increasing quartiles of cumulative menstrual months in premenopausal (Ptrend = 0.019) and postmenopausal Filipina (Ptrend = 0.008), in premenopausal (Ptrend = 0.0003) but not postmenopausal Chinese (Ptrend = 0.79), and in neither premenopausal (Ptrend = 0.092) nor postmenopausal (Ptrend = 0.75) Japanese Americans. For postmenopausal Filipina and Japanese, greater weight gain since age 18 (Ptrend = 0.019 and 0.053, respectively), high current body mass index (both Ptrend < 0.01), and greater waist circumferences (both Ptrend < 0.04) were statistically significant; these associations were weaker for postmenopausal Chinese women.

CONCLUSIONS

Cumulative menstrual months and body size factors were statistically significant risk factors for Filipina. Total menstrual months were associated with breast cancer among Chinese but not for Japanese, while body size factors were significantly associated with risk among Japanese but not among Chinese.

IMPACT

Characterization of breast cancer risk factors in Filipina will help to generate hypotheses for their high breast cancer incidence. Cancer Epidemiol Biomarkers Prev; 25(12); 1572-86. ©2016 AACR.

Comparative analysis of anthropometric indices of obesity as correlates and potential predictors of risk for hypertension and prehypertension in a population in Nigeria

Background:

Obesity is a well-established independent risk factor for hypertension and other cardiometabolic disorders. However, the best anthropometric index of obesity that predicts or associates strongly with hypertension and related conditions remains controversial and inconclusive.

Objective:

This study compared the performance of eight anthropometric indices of obesity: body mass index (BMI), ponderal index (PI), waist circumference (WC), hip circumference (HC), waist–hip ratio (WHR), waist–height ratio (WHtR), body adiposity index (BAI) and conicity index (CI) as correlates and potential predictors of risk of hypertension and prehypertension in a Nigerian population, and also the possible effect of combining two or more indices in that regard.

Methods:

This church-based, cross-sectional study was conducted in Anambra state, south-eastern Nigeria from 2012 to 2013. A total of 912 persons (436 male and 476 female) drawn randomly from three major cities (Awka, Onitsha and Nnewi) in the state participated in the study. Information on demography, medical history and lifestyle were obtained using a well-structured and validated questionnaire. The systolic/diastolic blood pressure and anthropometric measurements were taken by well-trained personnel. The resulting data were analysed using descriptive statistics, logistic regression, Poisson regression and receiver operating characteristic curve analysis.

Results:

The mean values of all the anthropometric indices studied increased from normotension, through prehypertension to hypertension in both genders. BMI, WC, HC and CI were significantly higher (p < 0.05) in females than males. All the anthropometric indices studied were significantly (p < 0.001 except for CI) correlated with systolic and diastolic blood pressure. BMI, WHtR, WC and PI (with higher correlation coefficients for blood pressure) showed the best potential potential to predict hypertension and prehypertension in the study: BMI (cut-off = 24.49, AUC = 0.698; cut-off = 23.62, AUC = 0.659), WHtR (cut-off = 0.55, AUC = 0.682; cut-off = 0.5, AUC = 0.636), WC (cut-off = 91.44, AUC = 0.692; cut-off = 82.55, AUC = 0.645), PI (cut-off = 14.45, AUC = 0.670; cut-off = 13.69, AUC = 0.639), in males; and BMI (cut-off = 24.44, AUC = 0.622; cut-off = 28.01, AUC = 0.609), WHtR (cut-off = 0.51, AUC = 0.624; cut-off = 0.6, AUC = 0.572), WC (cut-off = 96.62, AUC = 0.616; cut-off = 96.52, AUC = 0.584), PI (cut-off = 16.38, AUC = 0.619; cut-off = 17.65, AUC = 0.599), in females for hypertension and prehypertension, respectively. In predicting hypertension risk, WC and WHtR did not significantly improve the performance of BMI in the models when included using our decision rule. Overall, CI had a very poor discriminatory power for both conditions in this study.

Conclusion:

BMI, WHtR, WC and PI emerged the best predictors of hypertension risk, and BMI, WC and PI of prehypertension risk in this study. The combination of high-performing anthropometric indices in a model did not improve their performance. Therefore we recommend the simultaneous but independent use of BMI and either WC or WHtR for predicting hypertension, and BMI and WC for prehypertension risk, bearing in mind that both types of index (abdominal and general obesity) account for different forms of obesity.

Association of the SPT2 chromatin protein domain containing 1 gene rs17579600 polymorphism and serum lipid traits

SPT2 chromatin protein domain containing 1 gene (SPTY2D1) is a candidate gene for dyslipidemia. The single nucleotide polymorphism (SNP) of rs7934205 near SPTY2D1 locus was ethnic- and sex-specific associated with serum lipid levels in our previous study. Whether SPTY2D1 rs17579600 SNP and several environmental factors are associated with serum lipid profiles is unknown. A total of 712 participants of Han and 689 unrelated individuals of Mulao were included. The genotype and allele frequencies of SPTY2D1 rs17579600 SNP were different between the Han and Mulao populations (TT, 74.3% vs. 55.7%; TC, 17.6% vs. 31.2%, CC, 8.1% vs. 13.1%, P = 0.028; T, 83.1% vs. 71.3%; C, 16.9% vs. 28.7%, P = 0.044), and between males and females in the both ethnic groups. The levels of serum apolipoprotein (Apo) A1 in Han, triglyceride (TG) in Mulao, and total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), ApoA1 and ApoB in Mulao males were difference among the genotypes. The C allele carriers had higher ApoA1 in Han, lower TG in Mulao, and lower TC, LDL-C and ApoB and higher ApoA1 in Mulao males than the C allele non-carriers. Serum lipid parameters were also associated with several environmental factors in both ethnic groups. The differences suggesting there may be a racial/ethnic- and/or sex-specific association between the SPTY2D1 rs17579600 SNP and serum lipid parameters in some ethnic groups.

Gender-specific association of oxidative stress and inflammation with cardiovascular risk factors in Arab population

Background. The impact of gender difference on the association between metabolic stress and cardiovascular disease (CVD) remains unclear. We have investigated, for the first time, the gender effect on the oxidative and inflammatory stress responses and assessed their correlation with classical cardiometabolites in Arab population. Methods. A total of 378 adult Arab participants (193 females) were enrolled in this cross-sectional study. Plasma levels of CRP, IL-6, IL-8, TNF-α, ROS, TBARs, and PON1 were measured and correlated with anthropometric and cardiometabolite parameters of the study population. Results. Compared to females, males had significantly higher FBG, HbA1c, TG, and blood pressure but lower BMI, TC, and HDL (P < 0.05). After adjustment for BMI and WC, females had higher levels of ROS, TBARS, and CRP (P < 0.001) whereas males had increased levels of IL-8, IL-6, and TNF-α (P < 0.05). Moreover, after adjustment for age, BMI, and gender, the levels of TNF-α, IL-6, and ROS were associated with central obesity but not general obesity. Conclusion. Inflammation and oxidative stress contribution to CVD risk in Arab population linked to gender and this risk is better reflected by central obesity. Arab females might be at risk of CVD complications due to increased oxidative stress.