The visceral adiposity index is associated with insulin sensitivity and IGF-I levels in adults with growth hormone deficiency

Optimal cut‐off points of fat mass index and visceral adiposity index associated with type 2 diabetes mellitus

Background

Indices, based on anthropometrics with or without non‐anthropometric components, are predictive of cardio‐metabolic outcomes. Fat mass index (FMI) is similar to BMI except measured fat mass replaces body weight. The visceral adiposity index (VAI) combines anthropometric measures with lipid measurements TG/HDL. The relationship of these indices to incident type 2 diabetes (T2DM) has not been established. Therefore, we have evaluated the predictive power and optimal cut‐off points of FMI, and VAI with T2DM in a cross‐sectional population study.

Methods

These population‐based cross‐sectional study comprised 8411 adults aged 35–65 years using data from the Ravansar Non‐Communicable Diseases (RaNCD) cohort. VAI and FMI were defined as previously published. Optimal cut‐off points for association with incident T2DM were determined from receiver‐operating curves (ROC).

Results

The optimal cut‐off point for VAI was 4.86 (AUC: 0.673; 95% CI: 0.65–0.69) and FMI 9.3 (AUC: 0.57; 95% CI: 0.55–0.59), and for T2DM in our study population. The odds ratios (OR) for T2DM were nearly identical, for VAI 1.098 (95% CI: 1.08–1.11) and for FMI 1.08 (95% CI: 1.05–1.10).

Conclusions

In the current population study, VAI and FMI were weakly associated with T2DM. Therefore, it seems that anthropometric measures are unlikely to be strong mediators of T2DM compared to historical and other factors in the population studied.

We found that VAI had more predictive power to diagnose T2DM than FMI.

Vasculometabolic effects in patients with congenital growth hormone deficiency with and without GH replacement therapy during adulthood

PURPOSE

To evaluated the metabolic profiles and vascular properties in congenital growth hormone (GH) deficiency (GHD) and its replacement in adults.

PATIENTS AND METHODS

Cross-sectional study conducted in a single tertiary center for pituitary diseases. Eighty-one adult subjects were divided into three groups: (1) 29 GHD patients with daily subcutaneous GH replacement therapy (GHRT) during adulthood; (2) 20 GHD patients without GHRT during adulthood and (3) 32 controls. Only patients with adequate adherence to others pituitary hormone deficiencies were included. Anthropometric parameters, body composition by dual-energy X-ray absorptiometry, metabolic profiles and vascular properties (carotid intima media thickness, pulse wave velocity and flow-mediated dilation) were compared among the groups.

RESULTS

Waist-to-height ratio (WHR), body fat percentages and fat mass index (FMI) were lower in patients with GHRT than patients without GHRT during adulthood (0.49 ± 0.06 vs. 0.53 ± 0.06 p = 0.026, 30 ± 10 vs. 40 ± 11 p = 0.003 and 7.3 ± 4 vs. 10 ± 3.5 p = 0.041, respectively). In addition, association between longer GHRT and lower body fat percentage was observed (r =  - 0.326, p = 0.04). We found higher triglyceride (113.5 ± 62 vs. 78 ± 36, p = 0.025) and lower HDL cholesterol (51 ± 17 vs. 66 ± 23, p = 0.029) levels in patients without GHRT during adulthood in comparison to controls. No statistical differences were observed for vascular properties among the groups.

CONCLUSIONS

No differences in vascular properties were observed in congenital GHD adult patients with or without GHRT despite patients without GHRT had an unfavorable body composition. GHRT currently remains an individualized decision in adults with GHD and these findings bring new insight into the treatment and follow-up of these patients.

Effect of long-term growth hormone replacement on glucose metabolism in adults with growth hormone deficiency: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis was performed to summarize the long-term (more than 6 months) effect of growth hormone (GH) replacement therapy (GHRT) on glucose metabolism among adults growth hormone deficiency (AGHD) patients.

METHODS

We searched MEDLINE, EMBASE and the Cochrane Library databases from inception till March 2020 for relevant studies evaluating the effect of GHRT on glucose metabolism in AGHD patients. Results were stratified into two periods (6-12 months and more than12 months) according to the length of follow-up.

RESULTS

Thirty-three studies including 11 randomized controlled trials (RCTs) and 22 prospective open-label studies (POLs) were included in the meta-analysis. The findings of this meta-analysis showed that GH supplementation with a duration of 6-12 months among adults with growth hormone deficiency (GHD) significantly increased fasting plasma glucose (FPG) (SMD 0.37; 95% CI 0.25 to 0.49; I² = 0%; P < 0.00001), fasting insulin (FI) (SMD 0.2; 95% CI 0.08 to 0.33; I² = 9%; P = 0.001), glycated hemoglobin (HbA1c) (SMD 0.31; 95% CI 0.17 to 0.46; I² = 10%; P < 0.0001) and homeostasis model of assessment-insulin resistance (HOMA-IR) (SMD 0.28; 95% CI 0.08 to 0.47; I² = 13%; P = 0.006). Notably, GH intervention with a duration of more than 12 months showed no significant effect on FI (SMD 0.14; 95% CI - 0.09 to 0.37; I² = 0%; P = 0.24), HbA1c (SMD - 0.02; 95% CI - 0.3 to 0.26; I² = 72%; P = 0.89) and HOMA-IR levels (SMD 0.04; 95% CI - 0.24 to 0.31; I² = 0%; P = 0.80) in adults with GHD. However, FPG levels in AGHD were still significantly increased with more than one year intervention period (SMD 0.41; 95% CI 0.29 to 0.53; I² = 0%; P < 0.00001).

CONCLUSION

Overall, the current meta-analysis demonstrated that GHRT with a shorter duration (6-12 months) led to a deterioration in glucose metabolism including FPG, FI, HbA1c and HOMA-IR in AGHD patients. However, the negative effects of GH therapy on these glucose homeostasis parameters were not seen in longer duration of GHRT, except for FPG.

Performance of Two Novel Obesity Indicators for the Management of Metabolic Syndrome in Young Adults

BACKGROUND

Metabolic syndrome (MetS) is a pathophysiological change based on the abnormal metabolism of many substances. The study aims to investigate the performance of visceral adiposity index (VAI) and lipid accumulation product (LAP) of MetS in young adults.

METHODS

448 young adults aged between 19 and 24 years old in Qinhuangdao had been included in this cross-sectional study. Receiver operating characteristic (ROC) curve analyses were used to assess the accuracy of these two obesity indicators for MetS.

RESULTS

The prevalence of MetS was 2.0%. In male subjects, LAP had the highest area under the ROC curve (AUC) value (AUC = 0.963), followed by VAI (AUC = 0.937). In female subjects, LAP also had the highest AUC value (AUC = 0.931), followed by VAI (AUC = 0.861). No significant difference was found between the two obesity indicators (P > 0.05).

CONCLUSION

The two obesity indicators were valuable for the screening of MetS in young adults, and LAP was the simpler of the two.

Visceral adiposity index is a better predictor of type 2 diabetes than body mass index in Qatari population

The prevalence of type 2 diabetes (T2D) has increased recently in Qatar. Body mass index (BMI) is a predictor of T2D in many populations. However, BMI is based on height and weight measurements and not on body adiposity. Therefore, the utility of BMI for predicting the risk of T2D has been questioned. Visceral adiposity appears to be a better predictor of T2D.This study aimed to assess the relative effectiveness of visceral adiposity index (VAI) and body adiposity index (BAI), in comparison with BMI, for T2D among Qatari adults.A random sample of 1103 adult Qatari nationals and long term residents over 20 years old were included in this study. This data were obtained from the Qatar Biobank (QBB). We performed a multivariate logistic regression to examine the association between VAI, BAI, BMI, and T2D, and computed z-scores for VAI, BAI and BMI.VAI z-scores showed the strongest association with the risk of T2D (OR, 1.44; 95% CI: 1.24-1.68) compared with the z-scores for BAI (OR, 1.15; 95% CI: 0.93-1.43) and BMI (OR, 1.33; 95% CI: 1.11-1.59). ROC curve analysis showed that VAI was a stronger predictor than BAI and BMI (P < .0001). Subgroup analysis indicated that the association was stronger between VAI and T2D in Qatari women than in men.VAI was a stronger and an independent predictor of T2D compared to BAI and BMI among the Qatari adult population. Therefore, VAI could be a useful tool for predicting the risk of T2D among Qatari adults.

The Visceral Adipose Index in Relation to Incidence of Hypertension in Chinese Adults: China Health and Nutrition Survey (CHNS)

Hypertension is the most crucial single contributor to global burden of disease and mortality, while weight loss as a non-pharmacological strategy is recommended to reduce blood pressure. This study aims to examine the association between visceral adipose index (VAI) and hypertension in Chinese adults. Data were collected from the China Health and Nutrition Survey (CHNS), consisting of 8374 apparently healthy participants aged ≥18 years in the 2009 CHNS for cross-sectional analysis, and 4275 participants at entry from 2009 to 2011 for cohort analysis. Height, weight, waist circumference, blood pressure (BP), and blood lipid were measured. Information of population characteristics, smoking status, alcohol consumption, physical activity, and diet were determined by validated questionnaire. Higher VAI scores were significantly associated with higher BP levels and higher risk of hypertension after adjustment with potential confounders (all p-trend < 0.001). The adjusted hazard ratio of hypertension was 1.526 (95%CI: 1.194, 1.952; p-trend < 0.01) for participants in the highest quartile of VAI scores when compared with those in the lowest quartile after adjustment for age, physical activity, antihypertensive medication, total energy intake, salt intake, and other major lifestyle factors. VAI scores were significantly, longitudinally associated with hypertension development among apparently healthy Chinese adults.

Pasireotide treatment reduces cardiometabolic risk in Cushing's disease patients: an Italian, multicenter study

PURPOSE

Patients with Cushing's disease (CD) experience metabolic alterations leading to increased cardiovascular mortality. Recently, the visceral adiposity index (VAI) has been proposed as a marker of visceral adipose tissue dysfunction (ATD) and of the related cardiometabolic risk. We aimed to evaluate the impact of 12-month pasireotide treatment on cardiometabolic risk in CD patients.

METHODS

This is a multicentre, prospective, and observational study. Sixteen CD patients, referred to the Endocrine Units of the University Hospitals of Messina, Napoli, Padova, and Palermo (Italy), successfully treated with pasireotide for 12 month have been enrolled. In all patients, we assessed anthropometric, clinical, and biochemical parameters and calculated VAI, ATD severity, Framingham, and atherosclerotic cardiovascular disease (ASCVD) risk scores, before and after 6 and 12 months of treatment with pasireotide (1200-1800 mcg/daily).

RESULTS

Before starting pasireotide treatment, ATD was present in 7/16 patients (mild in 2/16, moderate in 3/16, and severe 2/16). After 12 months of treatment: (i) 24h-urinary free cortisol levels (p = 0.003), BMI (p < 0.001), waist circumference (p = 0.001), LDL-cholesterol (p = 0.033), total-cholesterol (p = 0.032), triglycerides (p = 0.030), VAI (p = 0.015), and ATD severity (p = 0.026) were significantly decreased as compared to baseline; (ii) ATD was present in only 1/16 patients; (iii) prevalence of diabetes mellitus (p = 0.015) and HbA1c levels (p = 0.001) were significantly increased as compared to baseline; (iv) Framingham and ASCVD risk scores were not significantly different from pre-treatment values.

CONCLUSIONS

Twelve-month pasireotide treatment significantly reduces VAI and ATD in CD patients. These positive effects on cardiometabolic risk occur despite no change in Framingham and ASCVD risk scores and the increase in the prevalence of diabetes mellitus.

Increased fibrosis: A novel means by which GH influences white adipose tissue function

OBJECTIVE

White adipose tissue (WAT) fibrosis - the buildup of extracellular matrix (ECM) proteins, primarily collagen - is now a recognized hallmark of tissue dysfunction and is increased with obesity and lipodystrophy. While growth hormone (GH) is known to increase collagen in several tissues, no previous research has addressed its effect on ECM in WAT. Thus, the purpose of this study is to determine if GH influences WAT fibrosis.

DESIGN

This study examined WAT from four distinct strains of GH-altered mice (bGH and GHA transgenic mice as well as two tissue specific GH receptor gene disrupted lines, fat growth hormone receptor knockout or FaGHRKO and liver growth hormone receptor knockout or LiGHRKO mice). Collagen content and adipocyte size were studied in all cohorts and compared to littermate controls. In addition, mRNA expression of fibrosis-associated genes was assessed in one cohort (6month old male bovine GH transgenic and WT mice) and cultured 3T3-L1 adipocytes treated with GH.

RESULTS

Collagen stained area was increased in WAT from bGH mice, was depot-dependent, and increased with age. Furthermore, increased collagen content was associated with decreased adipocyte size in all depots but more dramatic changes in the subcutaneous fat pad. Notably, the increase in collagen was not associated with an increase in collagen gene expression or other genes known to promote fibrosis in WAT, but collagen gene expression was increased with acute GH administration in 3T3-LI cells. In contrast, evaluation of 6month old GH antagonist (GHA) male mice showed significantly decreased collagen in the subcutaneous depot. Lastly, to assess if GH induced collagen deposition directly or indirectly (via IGF-1), fat (Fa) and liver (Li) specific GHRKO mice were evaluated. Decreased fibrosis in FaGHRKO and increased fibrosis in LiGHRKO mice suggest GH is primarily responsible for the alterations in collagen.

CONCLUSIONS

Our results show that GH action is positively associated with an increase in WAT collagen content as well as a decrease in adipocyte size, particularly in the subcutaneous depot. This effect appears to be due to GH and not IGF-1 and reveals a novel means by which GH regulates WAT accumulation.

Glucose Metabolism in Children With Growth Hormone Deficiency

BACKGROUND

The growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis has a fundamental impact on glucose metabolism. Therefore, both untreated GH deficiency (GHD) and GH treatment (GHT) may be associated with some metabolic alterations, although the abnormalities of glucose metabolism have been investigated by relatively few studies as main outcomes.

AIM

The present review summarizes the available data on glucose metabolism in children with GHD, providing an overview of the current state of the art in order to better clarify the real metabolic impact of GHD and GHT.

METHODS

Among all the existing studies, we evaluated all original studies that fulfilled our criteria for analysis reporting parameters of glucose metabolism as the primary or secondary objective.

RESULTS

The reported impact of GHD per se on glucose metabolism is quite homogeneous, with the majority of studies reporting no significant difference in metabolic parameters between GHD children and controls. Conversely, GHT proves to be more frequently associated with a subtle form of insulin resistance, while both fasting glucose and HbA1c levels remain almost always within the normal range.

CONCLUSION

The different methods to study glucose metabolism, the heterogeneity of the populations evaluated, the different doses of GH used together with the variable duration of follow-up may be responsible for discrepancy in the results. Long-term longitudinal studies having glucose homeostasis as their primary outcome are still needed in order better to clarify the real metabolic impact of GHD and GHT in children.

Relationship between IGF-I Concentration and Metabolic Profile in Children with Growth Hormone Deficiency: The Influence of Children's Nutritional State as well as the Ghrelin, Leptin, Adiponectin, and Resistin Serum Concentrations

BACKGROUND

Some, however not all, children with growth hormone deficiency (GHD) reveal a tendency towards metabolic disorders. Insulin-like growth factor I (IGF-I) is the main mediator of GH anabolic effects.

OBJECTIVE

The aim of the study was to compare ghrelin, adiponectin, leptin, resistin, lipid, glucose, and insulin concentrations in GHD children, depending on the IGF-I bioavailability.

METHODS

The analysis comprised 26 children with GHD, aged 5.7-15.3 yrs. Fasting serum concentrations of IGF-I, IGFBP-3, ghrelin, leptin, adiponectin, resistin, lipids, glucose, and insulin were measured. The GHD children were divided into two subgroups: (1) with lower IGF-I/IGFBP-3 molar ratio and (2) with higher IGF-I/IGFBP-3 molar ratio. The control group consisted of 39 healthy children, aged 5.1-16.6 yrs, of normal height and body mass.

RESULTS

GHD children with lower IGF-I/IGFBP-3 molar ratio were found to have a significantly lower body mass and insulin and triglyceride concentrations, as well as significantly higher ghrelin and adiponectin concentrations than GHD children with higher IGF-I/IGFBP-3.

CONCLUSIONS

A better metabolic profile characterised GHD children with low IGF-I bioavailability. This phenomenon may be the result of high adiponectin and ghrelin concentrations in those children and their influence on adipose tissue, glucose uptake, and orexigenic axis.