Sagittal abdominal diameter is associated with insulin sensitivity in Chinese hypertensive patients and their siblings

Sagittal abdominal diameter resembles waist circumference as a surrogate marker of insulin resistance in adolescents-Brazilian Metabolic Syndrome Study

OBJECTIVE

To evaluate the association of the sagittal abdominal diameter (SAD) with insulin resistance (IR) and metabolic syndrome (MetS) components, and to compare SAD with waist circumference (WC).

SUBJECTS/METHODS

This was a multicenter, cross-sectional study of 520 adolescents (10- to 18-years old). IR was assessed using the homeostasis model assessment of IR (HOMA-IR) and the hyperglycaemic clamp (n = 76).

RESULTS

SAD and WC were positively correlated with HOMA-IR (r = 0.637 and r = 0.653) and inversely correlated with the clamp-derived insulin sensitivity index (ISI) (r = -0.734 and r = -0.731); P < .001. In the multivariable linear regression analysis, SAD was positively associated with HOMA-IR (B = 0.046 ± 0.003) and inversely associated with the clamp-derived ISI (B = -0.084 ± 0.009) after adjusting for sex, age, and Tanner's stages (P < .001). When WC replaced the SAD, it was positively associated with HOMA-IR (B = 0.011 ± 0.001) and inversely associated with the clamp-derived ISI (B = -0.018 ± 0.002); P < .001. The values of the areas under the curves (AUC) were 0.823 and 0.813 for SAD and WC, respectively. In Bland-Altman analysis, there were agreement between both, SAD and WC, with the clamp-derived ISI (mean = 0.00; P > .05). The SAD and WC were positively associated with blood pressure, triglycerides, and uric acid, and inversely associated with high-density lipoprotein (HDL)-cholesterol after adjusting for sex, age, and Tanner's stages.

CONCLUSION

The SAD was associated with IR and MetS components, with a good discriminatory power for detecting IR. When compared to WC, SAD showed equivalent results.

Sagittal Abdominal Diameter, Waist Circumference, and BMI as Predictors of Multiple Measures of Glucose Metabolism: An NHANES Investigation of US Adults

The objective was to compare associations between sagittal abdominal diameter (SAD), waist circumference, and BMI to the oral glucose tolerance test (OGTT), along with fasting glucose, HbA1c, and HOMA-IR, in a nationally representative sample of 3582 US adults. The study also analyzed the effect of multiple covariates on the anthropometric and glucose metabolism associations. A cross-sectional design was used. SAD was assessed using an abdominal caliper. All other data were collected following strict NHANES protocols. The OGTT was the primary variable used to index glucose metabolism. Fasting glucose, HbA1c, and HOMA-IR were also evaluated. Results showed that mean ± SE values were as follows: SAD: 22.3 ± 0.1 cm, waist circumference: 98.0 ± 0.4 cm, BMI: 28.6 ± 0.2 kg/m2, OGTT: 113.9 ± 1.0 mg/dL, fasting glucose: 99.6 ± 0.3 mg/dL, HbA1c: 5.4 ± 0.01%, and HOMA-IR: 3.2 ± 0.1. Compared to waist circumference and BMI, SAD consistently emerged as the best predictor of glucose metabolism, before and after adjusting for the covariates, and with the sample stratified by gender, race, or age. SAD was not a better predictor of OGTT among normal-weight adults or non-Hispanic Black adults. Due to the ease of taking SAD measurements, we recommend that healthcare providers use this simple method to more precisely predict diabetes risk, especially among overweight and obese adults.

Inuit anthropometry and insulin resistance

OBJECTIVES

Due to the increasing prevalence of obesity among Inuit, a study was conducted in an Inuit community to evaluate the anthropometric correlates of indices of insulin resistance using the homeostasis model assessment index (IR(HOMA)) and the insulin sensitivity index (ISI(0,120)).

STUDY DESIGN

Data were collected as part of a health screening in a Baffin community in Nunavut, Canada, among adults 18 years of age and above.

METHODS

A total of 52 Inuit participated in the health screening of which 46 completed both the fasting and the 2-hour blood tests. Insulin sensitivity indices could be calculated on 45 participants.

RESULTS

Results for women indicated that in age-adjusted linear regression analyses, body mass index, waist circumference (WC) and percent body fat (%BF) predicted IR(HOMA), and ISI(0,120) (p < 0.05). For men, %BF predicted IR(HOMA), and WC and %BF predicted ISI0,120 (p < or = 0.05).

CONCLUSIONS

The present study suggests that increasing rates of obesity among Inuit will have health consequences and that anthropometry is a useful tool to indirectly assess insulin resistance/sensitivity.

Sagittal Abdominal Diameter as a Surrogate Marker of Insulin Resistance in an Admixtured Population--Brazilian Metabolic Syndrome Study (BRAMS)

Background

Sagittal abdominal diameter (SAD) has been proposed as a surrogate marker of insulin resistance (IR). However, the utilization of SAD requires specific validation for each ethnicity. We aimed to investigate the potential use of SAD, compared with classical anthropometrical parameters, as a surrogate marker of IR and to establish the cutoff values of SAD for screening for IR.

Methods

A multicenter population survey on metabolic disorders was conducted. A race-admixtured sample of 824 adult women was assessed. The anthropometric parameters included: BMI, waist circumference (WC), waist-to-hip ratio and SAD. IR was determined by a hyperglycemic clamp and the HOMA-IR index.

Results

After adjustments for age and total body fat mass, SAD (r = 0.23 and r = -0.70) and BMI (r = 0.20 and r = -0.71) were strongly correlated with the IR measured by the HOMA-IR index and the clamp, respectively (p < 0.001). In the ROC analysis, the optimal cutoff for SAD in women was 21.0 cm. The women with an increased SAD presented 3.2 (CI 95%: 2.1-5.0) more likelihood of having IR, assessed by the HOMA-IR index compared with those with normal SAD (p < 0.001); whereas women with elevated BMI and WC were 2.1 (95% CI: 1.4-3.3) and 2.8 (95% CI: 1.7-4.5) more likely to have IR (p < 0.001), respectively. No statistically significant results were found for waist-to-hip ratio.

Conclusions

SAD can be a suitable surrogate marker of IR. Understanding and applying routine and simplified methods is essential because IR is associated with an increased risk of obesity-related diseases even in the presence of normal weight, slight overweight, as well as in obesity. Further prospective analysis will need to verify SAD as a determinant of clinical outcomes, such as type 2 diabetes and cardiovascular events, in the Brazilian population.

Sagittal abdominal diameter is an independent predictor of all-cause and cardiovascular mortality in incident peritoneal dialysis patients

Backgrounds and Aims

Visceral fat has a crucial role in the development and progression of cardiovascular disease, the major cause of death in end-stage renal disease (ESRD). Although sagittal abdominal diameter (SAD), as an index of visceral fat, significantly correlated with mortality in the general population, the impact of SAD on clinical outcomes has never been explored in ESRD patients. Therefore, we sought to elucidate the prognostic value of SAD in incident peritoneal dialysis (PD) patients.

Methods

We prospectively determined SAD by lateral abdominal X-ray at PD initiation, and evaluated the association of SAD with all-cause and cardiovascular mortality in 418 incident PD patients.

Results

The mean SAD was 24.5±4.3 cm, and during a mean follow-up of 39.4 months, 97 patients (23.2%) died, and 49.4% of them died due to cardiovascular disease. SAD was a significant independent predictor of all-cause [3rd versus 1st tertile, HR (hazard ratio): 3.333, 95% CI (confidence interval): 1.514–7.388, P = 0.01; per 1 cm increase, HR: 1.071, 95% CI: 1.005–1.141, P = 0.03] and cardiovascular mortality (3rd versus 1st tertile, HR: 8.021, 95% CI: 1.994–32.273, P = 0.01; per 1 cm increase, HR: 1.106, 95% CI: 1.007–1.214, P = 0.03). Multivariate fractional polynomial analysis also showed that all-cause and cardiovascular mortality risk increased steadily with higher SAD values. In addition, SAD provided higher predictive value for all-cause (AUC: 0.691 vs. 0.547, P<0.001) and cardiovascular mortality (AUC: 0.644 vs. 0.483, P<0.001) than body mass index (BMI). Subgroup analysis revealed higher SAD (≥24.2 cm) was significantly associated with all-cause mortality in men, women, younger patients (<65 years), and patients with lower BMI (<22.3 kg/m²).

Conclusions

SAD determined by lateral abdominal X-ray at PD initiation was a significant independent predictor of all-cause and cardiovascular mortality in incident PD patients. Estimating visceral fat by SAD could be useful to stratify mortality risk in these patients.

Endothelin Type A Receptor Genotype is a Determinant of Quantitative Traits of Metabolic Syndrome in Asian Hypertensive Families: A SAPPHIRe Study

Co-heritability of hypertension and insulin resistance (IR) within families not only implies genetic susceptibility may be responsible for these complex traits but also suggests a rational that biological candidate genes for hypertension may serve as markers for features of the metabolic syndrome (MetS). Thus we determined whether the T323C polymorphism (rs5333) of endothelin type A (ETA) receptor, a predominant receptor evoking potent vasoconstrictive action of endothelin-1, contributes to susceptibility to IR-associated hypertension in 1694 subjects of Chinese and Japanese origins. Blood pressures (BPs) and biochemistries were measured. Fasting insulin level, insulin-resistance homeostasis model assessment (HOMAIR) score, and area under curve of insulin concentration (AUCINS) were selected for assessing insulin sensitivity. Genotypes were obtained by methods of polymerase chain reaction-restriction fragment length polymorphism. Foremost findings were that minor allele frequency of the T323C polymorphism was noticeable lower in our overall Asian subjects compared to multi-national population reported in gene database; moreover both the genotypic and allelic frequencies of the polymorphism were significantly different between the two ethnic groups we studied. The genotype distributions at TT/TC/CC were 65, 31, 4% in Chinese and 51, 41, 8% in Japanese, respectively (p < 0.0001). Additionally, carriers of the C homozygote revealed characteristics of IR, namely significantly higher levels of fasting insulin, HOMAIR score, and AUCINS at 29.3, 35.3, and 39.3%, respectively, when compared to their counterparts with TT/TC genotypes in Chinese. Meanwhile, the CC genotype was associated with a higher level of high density lipoprotein cholesterol in Japanese. No association of the polymorphism with BP was observed. This study demonstrated for the first time that T323C polymorphism of ETA receptor gene was associated with an adverse insulin response in Chinese and a favorite atherogenic index in Japanese.

Sagittal abdominal diameter as a marker of inflammation and insulin resistance among immigrant women from the Middle East and native Swedish women: a cross-sectional study

Background

Immigrant women from the Middle East have elevated risk of cardiovascular disease. Sagittal abdominal diameter (SAD), a simple marker of intra-abdominal fat, predicts insulin resistance and cardiovascular mortality in men. Its usefulness in immigrant women is however unknown. To investigate the predictive role of SAD compared to other anthropometric measures, we examined a random sample of native-Swedes and immigrant women from the Middle East living in Sweden.

Methods

157 women participated in the study; 107 immigrants and 50 natives. Anthropometric measurements (SAD, body mass index [BMI], waist circumference [WC] and waist-to-hip ratio [WHR]; all measured in supine position) and cardiovascular risk factors (C-reactive protein [CRP], insulin, glucose, insulin resistance [HOMA-IR], blood pressure and serum lipids) were assessed. The anthropometric measures were compared in their relation to cardiovascular risk factors using linear regression analyses.

Results

Overall, SAD showed a slightly higher correlation with most cardiovascular risk factors, especially insulin resistance, insulin, CRP, apolipoprotein B and triglycerides (all P-values < 0.01) than other anthropometric measures. BMI was however a better predictor of HDL cholesterol. SAD explained a greater proportion of the variation of insulin resistance and CRP levels, even independently of the other anthropometric measures.

Conclusion

SAD identifies insulin resistance, subclinical inflammation or raised serum lipids in a Swedish population with a large proportion of immigrant women from the Middle East. If these results could be confirmed in a larger population, SAD could be a more clinically useful risk marker than other anthropometric measures in women at high risk of cardiovascular disease.

Surrogate estimates of insulin sensitivity in subjects with hypertension

The purpose of the study is to compare surrogate estimates of insulin sensitivity with a directly measured insulin sensitivity index, steady-state plasma glucose (SSPG) from insulin suppression test (IST), in subjects with hypertension. Two hundred and twenty-eight hypertensive patients who received IST for SSPG were included for analysis. Estimates from fasting measurements alone, homeostasis model assessment for insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI)), and indices from fasting and/or 2 h samples (ISI(0,120) and ISI(TX)) were calculated. In addition to Pearson and partial correlations, variance-component models were used to test the relationship between surrogate estimates of insulin sensitivity and SSPG. A large proportion of variance owing to covariates in the variance-component models indicated the goodness of model fit, irrespective of the independence among variables. SSPG was positively correlated with logarithmic transformation (Log) (HOMA-IR) and negatively correlated with QUICKI, Log (ISI(0,120)) and ISI(TX) (all P<0.0001). Log (ISI(0,120)) seemed to have a better correlation with SSPG (r=-0.72) than other measures in partial correlation. The proportion of variance owing to all covariates of Log (ISI(0,120)) and ISI(TX) were larger than those of Log (HOMA-IR) and QUICKI in the variance-component models. After adjustments for demographic and obesity covariates, the proportion of variance explained by Log (ISI(0,120)) were largest among the surrogate measures in the variance-component models. Our results showed that ISI(0,120) and ISI(TX) correlated better with SSPG than those used fasting measures alone (HOMA-IR and QUICKI). Log (ISI(0,120)) currently showing the strongest association with SSPG than other estimates is adaptable for use in large studies of hypertension.

Sagittal abdominal diameter is a strong anthropometric marker of insulin resistance and hyperproinsulinemia in obese men

OBJECTIVE

It is clinically important to find noninvasive markers of insulin resistance and hyperproinsulinemia because they both predict cardiovascular and diabetes risk. Sagittal abdominal diameter (SAD) or "supine abdominal height" is a simple anthropometric measure previously shown to predict mortality in men, but its association with insulin resistance and hyperproinsulinemia is unknown.

RESEARCH DESIGN AND METHODS

In a common high-risk group of 59 moderately obese men (aged 35-65 years, BMI 32.6 +/- 2.3 kg/m(2)), we determined anthropometry (SAD, BMI, waist girth, and waist-to-hip ratio [WHR]); insulin sensitivity (euglycemic-hyperinsulinemic clamp); and plasma concentrations of intact proinsulin, specific insulin, C-peptide, glucose, and serum IGF binding protein-1 (IGFBP-1). To compare SAD with other anthropometric measures, univariate and multiple regression analyses were used to determine correlations between anthropometric and metabolic variables.

RESULTS

SAD showed stronger correlations to all measured metabolic variables, including insulin sensitivity, than BMI, waist girth, and WHR. SAD explained the largest degree of variation in insulin sensitivity (R(2) = 0.38, P < 0.0001) compared with other anthropometric measures. In multiple regression analyses, including all anthropometric measures, SAD was the only independent anthropometric predictor of insulin resistance (P < 0.001) and hyperproinsulinemia (P < 0.001).

CONCLUSIONS

In obese men, SAD seems to be a better correlate of insulin resistance and hyperproinsulinemia (i.e., cardiovascular risk) than other anthropometric measures. In overweight and obese individuals, SAD could represent a simple, cheap, and noninvasive tool that could identify the most insulin resistant in both the clinic and clinical trials evaluating insulin sensitizers. These results need confirmation in larger studies that also include women and lean subjects.