Influence of waist on adiponectin and insulin sensitivity in adolescence

Cardiometabolic Changes in Response to a Calorie-Restricted DASH Diet in Obese Older Adults

Objective: To examine the response of a calorie-restricted Dietary Approaches to Stop Hypertension diet on indicators of cardiometabolic health in a cohort of sedentary obese older adults. Design: This was a controlled-feeding trial with a parallel design. Each participant consumed either 3 oz (85 g; n = 15) or 6 oz (170.1 g; n = 13) of lean fresh beef within a standardized calorie-restricted DASH-like diet for 12-weeks. Fasted blood samples were collected and used to measure conventional biomarkers of cardiovascular, metabolic and inflammatory health. Participants: Caucasian older (70.8 years), obese (BMI: 32 ± 6.9 kg/m²; WC: 101 ± 16.4 cm) females (n = 17) and males (n = 11) from the rural community of Brookings, South Dakota. Results: 28 participants completed the 12-week feeding trial, with no differences (p > 0.05) among the biomarkers of cardiometabolic health between the 3 and 6 oz beef intake groups. However, when the beef intake groups were combined, all biomarkers changed concentration in response to the intervention diet. Total cholesterol (p < 0.001), LDL-C (p = 0.004), HDL-C (p < 0.0001), insulin (p = 0.014), glucose (p = 0.008), HOMA-IR (p < 0.05), IL-12 (p < 0.001), and CRP (p = 0.006) all decreased in response to the study diet. IGF-1 (p < 0.001) and IL-8 (p = 0.005) increased in response to the intervention. Correlations among cardiometabolic biomarkers and body composition measures were observed. By study end, the decrease in insulin (R ² = 0.22; P = 0.012) and HOMA-IR (R ² = 0.22; P = 0.01) was positively correlated with the decrease in waist circumference. The increase in IGF-1 was significantly correlated with the decrease in waist circumference (R ² = 0.21; p = 0.014). The increase in IGF-1 was significantly correlated with the increase in sit-to-stand (R ² = 0.21; p = 0.016). The increase in IL-8 was significantly correlated with decreases in total cholesterol (R ² = 0.24; P = 0.008), LDL-C (R ² = 0.17; P = 0.031) and glucose (R ² = 0.44; P = 0.0001). Conclusions: These findings suggest that a DASH-like diet with restricted calories may potentially improve biomarkers of cardiometabolic health in sedentary obese older adults. These results also point to interrelationships between body composition changes and changes in cardiometabolic biomarkers. Lastly, regardless of meat intake amount, positive impacts on cardiometabolic biomarkers were observed in this cohort of older adults with an obese phenotype.

Temporal relationship between body mass index and triglyceride-glucose index and its impact on the incident of hypertension

BACKGROUND AND AIMS

Obesity and insulin levels can influence each other by metabolism. However, their temporal sequences and influence on hypertension are generally unknown, especially in Chinese adults. Recently, some scholars have proposed that triglycerides-glucose index (TyG) is an important indicator of insulin resistance. The study aims to describe the relationship between body mass index (BMI) and TyG index and its impact on hypertension.

METHODS AND RESULTS

A total of 4081 adults (56.33% women) without antihypertensive, hypoglycemic or lipid-lowering medications were selected for the present study. Measurements of BMI and TyG index were obtained twice from 2012 to 2017. Cross-lagged panel analysis was used to describe the temporal sequences between BMI and TyG index, and the effect of their temporal relationship patterns on hypertension was explored through mediation analysis. After adjusting for confounding factors (age, sex, ethnicity et al.), the cross-lagged path coefficient from baseline BMI to follow-up TyG (ρ₂ = 0.135, P < 0.001) was significantly greater than the path coefficient from baseline TyG to follow-up BMI (ρ₁ = 0.043, P < 0.001), and P < 0.001 for the difference between ρ₁ and ρ₂. Furthermore, the sensitivity analyses between women and men revealed identical findings. In addition, TyG index mediation effect on BMI-hypertension was estimated to be 38.45% (P < 0.001) in total population, 25.24% in women and 57.35% in men.

CONCLUSION

These results provided evidence that the temporal relationship between BMI and insulin resistance is reciprocal and a higher BMI precedes hyperinsulinemia in Chinese adults. This relationship plays an essential role in the development of hypertension, while there is a difference between women and men.

Genetic and Non-Genetic Determinants of Circulating Levels of Adiponectin in a Cohort of Chilean Subjects

BACKGROUND

Low adiponectin levels have been associated with obesity, diabetes, coronary disease and polymorphisms. The aim of this study was to assess the clinical and genetic factors related to adiponectin levels in a Chilean adult population.

METHODS

Four groups of 27 individuals, stratified by gender and abdominal obesity, were included in this cross-sectional study. Physical activity level, cardiovascular risk factors and therapy were assessed. Anthropometric measurements, adiponectin, glucose, insulin, hs-CRP, rs1501299, rs2241766, rs266729 and rs17300539 single nucleotide polymorphisms of the adiponectin gene were determined.

RESULTS

Adiponectin levels were inversely correlated with waist circumference, waist-to-hip ratio, weight, body mass index, insulin levels, homeostasis model insulin resistance index (HOMA-IR) and physical activity. Mean adiponectin levels were lower in men (10.1 ± 3.6 vs 11.9 ± 2.9 μg/mL, p = 0.0051), obese (9.9 ± 3.2 vs 12.1 ± 3.3, p < 0.01), physically inactive (8.9 ± 3.2 vs 11.0 ± 2.8, p = 0.015) and insulin-resistant individuals (10.2 ± 3.1 vs 12.9 ± 3.9; p = 0.005). Adiponectin levels were lower in subjects with GG genotype (rs1501299) compared with those with TT or GT variants (6.9 ± 4.6 vs 12.2 ± 2.9 and 11.5 ± 3.4 μg/mL, p = 0.006) but were similar in the other polymorphisms studied.

CONCLUSION

Lower adiponectin levels were related to gender, abdominal obesity, physical activity and insulin resistance and were less influenced by the polymorphisms studied.

[Adiponectin levels in breast milk of overweight/obese and normal weight mothers in the metropolitan area of Monterrey, México]

BACKGROUND

Given the current epidemic of childhood obesity, it has become increasingly important to understand the risks and protective factors associated with this disease. Breastfeeding has been identified as a protective factor; however, the mechanism responsible has not been elucidated. One of the current theories analyzes the role of hormones in breast milk, with special emphasis on adiponectin. This study aims to compare adiponectin levels in breast milk of mothers with normal weight with those in breast milk of overweight/obese mothers as well as to correlate these levels with the infant's weight gain.

METHODS

Forty samples of breast milk were analyzed for adiponectin levels using ELISA, 20 from mothers with normal weight and 20 from overweight/obese mothers.

RESULTS

Adiponectin levels were lower in breast milk obtained from overweight/obese mothers than in breast milk from mothers with normal weight (p <0.05). When comparing infant weight gain, those fed with breast milk containing higher concentrations of adiponectin had a lower weight gain than those fed with breast milk containing low levels of the hormone (p <0.05).

CONCLUSIONS

There is a strong negative correlation between mothers' BMI and adiponectin levels in breast milk. Mothers with a higher BMI had lower adiponectin levels in their breast milk. There is also a negative relationship between adiponectin levels in breast milk and weight gain of breastfed infants. Infants breast fed with adiponectin-rich breast milk had a lower weight gain.

SNPs in the adiponectin receptor 2 gene and their associations with chicken performance traits

The adiponectin receptor 2 (ADIPOR2) is a receptor for both globular and full-length adiponectin. In the current study, two genetic variations in ADIPOR2 gene were identified in an F2 resource population of Gushi chicken and Anka broiler. Association analysis between the two SNPs and chicken performance traits were determined using the linear mixed model. The data revealed that the g.34490C > T mutation in intron 3 was significantly associated with liver weight and globulin, the g.35363T > C polymorphism in exon 5 was significantly associated with body weights at 6, 10, and 12 weeks of age. Both polymorphisms have no significant effects on serum glucose and fat-related traits. The g.34490C > T mutation might play an important role in regulating liver weight. The g.35363T > C polymorphism does contribute in a significant manner to growth traits at the medium and later development stage but it is uncertain whether it could be a molecular marker for liver disease.

Associations between two single nucleotide polymorphisms of the adiponectin gene, its circulating concentrations and cardiometabolic risk factors in prepubertal children with and without abdominal obesity

BACKGROUND

The adiponectin gene has been identified as a susceptibility locus for metabolic syndrome, diabetes and cardiovascular disease.

AIM

To examine the influence of two single nucleotide polymorphisms (SNPs) of this gene (+276G>T and +45T>G) on circulating adiponectin concentrations, and to evaluate their relationship with adiposity and cardiometabolic risk factors in prepubertal children with and without abdominal obesity.

MATERIAL AND METHODS

168 children (78M, 6-10 yr) were examined, divided into three groups based on waist circumference (WC). Auxological and biochemical parameters were measured by standard procedures. Adiponectin SNPs were genotyped using TaqMan allelic discrimination assays.

RESULTS

Adiponectin concentration correlated inversely with measures of adiposity (rBMIz-score=-0.211, pBMIz-score=0.007; rwc=-0.210, pwc=0.008; rwc/height=-0.215, pwc/height=0.006), and was significantly influenced by blood glucose, insulin and systolic blood pressure (SBP). The +276T-allele carriers had higher SBP and diastolic BP compared to GG-homozygotes (p<0.05), and expressed higher obesity-related measures and lower adiponectin concentrations. As to the +45T>G SNP, the GGsubject had higher total cholesterol and LDL-C concentrations compared to the T-allele carriers (p<0.05), showing worse obesity measures, higher triglyceride, glucose and insulin and lower serum adiponectin values.

CONCLUSION

Genetic variants of the adiponectin gene had an impact on adiposity, adiponectin concentrations and some cardiometabolic variables among prepubertal children.

Adiponectin in eutrophic and obese children as a biomarker to predict metabolic syndrome and each of its components

BACKGROUND

Obesity is associated with the rise of noncommunicable diseases worldwide. The pathophysiology behind this disease involves the increase of adipose tissue, being inversely related to adiponectin, but directly related to insulin resistance and metabolic syndrome (MetS). Therefore, this study aimed to determine the relationship between adiponectin levels with each component of MetS in eutrophic and obese Mexican children.

METHODS

A cross sectional study was conducted in 190 school-age children classified as obese and 196 classified as eutrophic. Adiponectin, glucose, insulin, high density lipoprotein cholesterol (HDL-C) and triglycerides were determined from a fasting blood sample. Height, weight, waist circumference, systolic and diastolic blood pressures (BP) were measured; MetS was evaluated with the IDF definition. The study groups were divided according to tertiles of adiponectin, using the higher concentration as a reference. Linear regression analysis was used to assess the association between adiponectin and components of the MetS. Finally, stepwise forward multiple logistic regression analysis controlling for age, gender, basal HOMA-IR values and BMI was performed to determine the odds ratio of developing MetS according to adiponectin tertiles.

RESULTS

Anthropometric and metabolic measurements were statistically different between eutrophic and obese children with and without MetS (P <0.001). The prevalence of MetS in obese populations was 13%. Adiponectin concentrations were 15.5 ± 6.1, 12.0 ± 4.8, 12.4 ± 4.9 and 9.4 ± 2.8 μg/mL for eutrophic and obese subjects, obese without MetS, and obese with MetS, respectively (P <0.001). Obese children with low values of adiponectin exhibited a higher frequency of MetS components: abdominal obesity, 49%; high systolic BP, 3%; high diastolic BP, 2%; impaired fasting glucose, 17%; hypertriglyceridemia, 31%; and low HDL-C values, 42%. Adjusted odds ratio of presenting MetS according to adiponectin categories was 10.9 (95% CI 2.05; 48.16) when the first tertile was compared with the third.

CONCLUSION

In this sample of eutrophic and obese Mexican children we found that adiponectin concentrations and MetS components have an inversely proportional relationship, which supports the idea that this hormone could be a biomarker for identifying individuals with risk of developing MetS.

Development of associations among central adiposity, adiponectin and insulin sensitivity from adolescence to young adulthood

OBJECTIVE

To examine associations of central adiposity, serum adiponectin and clamp-derived insulin sensitivity in a single longitudinal cohort from early adolescence to young adulthood.

METHODS

The cohort was examined three times at mean ages 15 years (n = 308), 19 years (n = 218) and 22 years (n = 163). Insulin sensitivity was measured with the euglycaemic hyperinsulinaemic clamp. Circulating adiponectin was measured by enzyme-linked immunosorbent assay. Computed tomography scans were used at mean age 22 to compute subcutaneous and visceral abdominal fat volume. Partial Pearson correlations and linear regression were used to examine cross-sectional associations at each examination.

RESULTS

The moderate negative correlation between waist circumference and adiponectin was significant and essentially unchanged from mean age 15 (-0.32, P < 0.0001) to mean age 22 (-0.29, P < 0.002), whereas the negative correlation between waist circumference and insulin sensitivity and the positive correlation between adiponectin and insulin sensitivity increased steadily in magnitude to mean age 22 (-0.29, P = 0.0002; and 0.32, P < 0.0001, respectively). In regression models including both visceral and subcutaneous fat, only visceral fat was significantly associated with insulin sensitivity, while only subcutaneous fat was nearly significantly associated with adiponectin.

CONCLUSIONS

This study shows that the significant negative relationship between waist circumference and adiponectin predated the development of significant relationships between insulin sensitivity and both waist circumference and adiponectin. It also shows that adiponectin is more closely related to subcutaneous fat and insulin sensitivity is more closely related to visceral fat in young adults.

Polymorphism of adiponectin (45T/G) and adiponectin receptor-2 (795G/A) in an Iranian population: relation with insulin resistance and response to treatment with pioglitazone in patients with type 2 diabetes mellitus

Adiponectin, an adipose-derived plasma protein, is reduced in patients with obesity and type 2 diabetes. Thiazolidinediones can increase adiponectin levels and improve insulin sensitivity. This study investigated the associations between type 2 diabetes and two single-nucleotide polymorphisms in the adiponectin (45T/G) and adiponectin receptor-2 gene (795G/A), and investigated whether these genetic variants affect the response to pioglitazone in Iranian patients with type 2 diabetes. We genotyped 128 non-diabetic participants and 101 patients with type 2 diabetes for 45T/G and 795G/A with polymerase chain reaction-restriction fragment length polymorphism assays. Patients were treated with pioglitazone for 12 weeks, after which we compared laboratory parameters in these two groups. Fasting blood sugar differed significantly in individuals with different 795G/A genotypes after pioglitazone treatment (P = 0.009). The mean decrease in insulin/glucose ratio after treatment also differed significantly in individuals with different 45T/G genotypes (P = 0.035). The T allele frequency for 45T/G was 87.11% in controls versus 81.68% in patients (P = 0.071). The TG and GG genotypes were more frequent in patients (P = 0.032). The G allele frequency for 795G/A was 76.17% in controls versus 80.20% in patients (P = 0.179). 795G/A variants were not significantly different between patient and control group. The adiponectin gene 45T/G mutation may be an important determinant of type 2 diabetes in the Iranian population. However, adiponectin 45T/G and adiponectin receptor-2 795G/A polymorphisms were not significantly associated with the response to pioglitazone in our sample.

Obesity modifies the relations between serum markers of dairy fats and inflammation and oxidative stress among adolescents

Pentadecanoic acid (15:0) and heptadecanoic acid (17:0), the dairy-specific saturated fatty acids have been inversely, while inflammation and oxidative stress have been positively related to the risk of cardiovascular disease (CVD). Both fatty acid metabolism and inflammation and oxidative stress may be influenced by adiposity. In the current cross-sectional analyses among adolescents (mean age 15 years), we determined whether overweight status modified the associations between dairy fatty acids (pentadecanoic acid (15:0) and heptadecanoic acid (17:0)) represented in serum phospholipids (PL) and markers of inflammation and oxidative stress. Six biomarkers for inflammation and oxidative stress were analyzed, including circulating adiponectin, C-reactive protein (CRP), cytokines interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), and urinary 15-keto-dihydro-PGF2α (15-keto) and 8-iso-PGF2α (F2-iso). Generalized linear regression analyses, adjusted for age, gender, race, tanner score, total energy intake and physical activity, revealed that PL dairy fatty acids were inversely associated with CRP, F2-iso and 15-keto in overweight, but not in normal weight adolescents (all P(interaction) < 0.05). However, higher level of PL dairy fatty acids was associated with lower IL-6 among all adolescents. Further adjustment for dietary intake of calcium, vitamin D, protein, total flavonoids, and ω-3 fatty acids did not materially change the findings. Dairy-specific saturated fats, i.e., 15:0 and 17:0 fatty acids, may contribute to the potential health benefits of dairy products, especially for overweight adolescents.

Distribution and genotype frequency of adiponectin (+45 T/G) and adiponectin receptor2 (+795 G/A) single nucleotide polymorphisms in Iranian population

The Adiponectin (ADIPOQ) gene encodes adipose tissue-secreted hormone, Adiponectin, which is secreted to the bloodstream by adipocytes. Adiponectin is a hormone with anti-inflammatory and anti-atherogenic properties and plays a significant role in insulin sensitivity and obesity. The genetic variations in ADIPOQ gene change the circulating adiponectin level and may cause insulin resistance. The aim of the present study is to evaluate the frequency of a common single nucleotide polymorphism (SNP) of ADIPOQ gene (+45T/G) and adiponectin receptor-2 (ADIPOR2) gene (+795G/A) in Iranian population and to correlate these data with other populations. A hundred healthy volunteers were enrolled to identify the genotype of ADIPOQ gene (+45T/G) and ADIPOR2 gene (+795G/A). This was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Genotype frequencies for ADIPOQ (+45T/G) were 0.789 for TT, 0.164 for TG, and 0.0468 for GG. Allelic frequencies were 0.87 and 0.13 for T and G, respectively. Genotype frequencies for ADIPOR2 (+795G/A) were 0.09 for AA, 0.3 for AG, and 0.61 for GG; allelic frequencies were 0.24 for A and 0.76 for G. Comparisons between ADIPOQ and ADIPOR2 polymorphisms in Iranian population with those in other populations showed significant differences.

Gender differences exist in the association of leptin and adiponectin levels with insulin resistance parameters in prepubertal Arab children

AIM

Differences in correlations between leptin, adiponectin and insulin resistance in children exist in different ethnic populations. No such information is available in Arab children. This study aims to fill this gap.

METHODS

Three hundred and twenty-five prepubertal children were recruited in this cross-sectional study. Body mass index (BMI), waist and hip circumferences and fasting glucose were measured by standard procedures. Serum insulin, leptin and adiponectin were assayed by ELISA.

RESULTS

Leptin and adiponectin levels were significantly correlated with anthropometric parameters, HOMA-IR and insulin in all subjects and with fasting glucose in girls only. Correlations of adiponectin with HOMA-IR and insulin in boys and of leptin with insulin in girls were independent of BMI, waist and hip circumferences.

CONCLUSION

Gender differences exist in the distribution of adipocytokines in prepubertal children. The associations of adipocytokines with obesity biomarkers in prepubertal children suggest a causal link between childhood obesity and the risk of an early diabetes onset.

Can hormones contained in mothers' milk account for the beneficial effect of breast-feeding on obesity in children?

Nutrition and growth during infancy are an emerging issue because of their potential link to metabolic health disorders in later life. Moreover, prolonged breast-feeding appears to be associated with a lower risk of obesity than formula feeding. Human milk is a source of various hormones and growth factors, namely adipokines (leptin and adiponectin), ghrelin, resistin and obestatin, which are involved in food intake regulation and energy balance. These compounds are either not found in commercial milk formulas or their presence is still controversial. Diet-related differences during infancy in serum levels of factors involved in energy metabolism might explain anthropometric differences and also differences in dietary habits between breast-fed (BF) and formula-fed (FF) infants later in life, and may thus have long-term health consequences. In this context, the recent finding of higher leptin levels and lower ghrelin levels in BF than in FF infants suggests that differences in hormonal values together with different protein intake could account for the differences in growth between BF and FF infants both during infancy and later in life. In this review, we examine the data related to hormones contained in mothers' milk and their potential protective effect on subsequent obesity and metabolic-related disorders.

The association of SNPs in ADIPOQ, ADIPOR1, and ADIPOR2 with insulin sensitivity in a cohort of adolescents and their parents

Few studies have examined the association of SNPs in the adiponectin (ADIPOQ) and adiponectin receptor 1 and 2 (ADIPOR1, ADIPOR2) genes with the euglycemic clamp, i.e. the gold standard measure of insulin sensitivity. The association of comprehensive tag SNPs in these genes with insulin sensitivity was examined in a cohort of adolescents and their parents. Probands and siblings (n=441, mean age=17.9 years) were recruited along with their parents (n=262, mean age=47.9 years). Typed SNPs included 21 SNPs in ADIPOQ, 7 SNPs in ADIPOR1, and 13 SNPs in ADIPOR2. Mixed model linear regression was used to test the association of SNPs with euglycemic-clamp derived insulin sensitivity. All analyses were stratified by race. After corrections to account for multiple testing and the linkage disequilibrium structure of the genes, one SNP in the ADIPOQ gene (rs822393) was significantly associated with insulin sensitivity in white subjects. In whites, six SNPs in ADIPOQ, one SNP in ADIPOR1 and one SNP in ADIPOR2 were associated with insulin sensitivity at the P<0.05 level. In African Americans, two SNPs in ADIPOR1 were associated with insulin sensitivity at the P<0.05 level. These results suggest that a variant in the ADIPOQ gene influences levels of insulin sensitivity and age may modify the effects of this variant. There are several other variants in ADIPOQ, ADIPOR1, and ADIPOR2 that may influence insulin sensitivity and these variants should be further investigated in other populations.