Lipid accumulation in overweight type 2 diabetic subjects: relationships with insulin sensitivity and adipokines

The Relationship between the Lipid Accumulation Product and Beta-cell Function in Korean Adults with or without Type 2 Diabetes Mellitus: The 2015 Korea National Health and Nutrition Examination Survey

AIMS

This study was conducted to assess the relationship between the lipid accumulation product index (LAP) and the homeostasis model assessment for insulin resistance (HOMA-IR) and beta-cell function (HOMA-B) in Korean adults with or without type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

The study was carried out using data from the 2015 Korean National Health and Nutrition Examination Survey (KNHANES) and included 4,922 adults aged 20 or older.

RESULTS

There were several key findings. First, in overall population, after adjusting for related variables, HOMA-IR (p < .001) and HOMA-B (p < .001) level were positively associated with quartiles of LAP. Second, in non-T2DM group, HOMA-IR (p < .001) and HOMA-B level (p < .001) were positively associated with quartiles of LAP. Third, in T2DM group, HOMA-IR (p < .001) level was positively associated with the quartiles of LAP, but HOMA-B (p = .153) level was not significant. In addition, HOMA-B level was increased with an increasing metabolic syndrome component in non-T2DM (p < .001) but not in T2DM (p = .267).

CONCLUSIONS

LAP was positively associated with both HOMA-IR and HOMA-B in non-diabetic Korean adults. However, LAP was positively associated with HOMA-IR in Korean adults with T2DM, while the association with HOMA-B was not significant.

Association Analysis of LEP Signaling Pathway with Type 2 Diabetes Mellitus in Chinese Han Population from South China

Objective

This study is aimed at analyzing the relationship between leptin (LEP) signaling pathway and type 2 diabetes mellitus (T2DM) and at providing support for molecular genetic research on the pathogenesis of T2DM in Chinese Han population.

Methods

A case-control study was designed, including 1092 cases with T2DM and 1092 healthy controls of Chinese Han origin recruited from ten hospitals in Guangdong Province, Southern China. Twenty-three single nucleotide polymorphisms (SNPs) of 15 genes in LEP signaling pathway were genotyped by SNPscan™ kit. The Pearson chi-square test, Cochran-Armitage trend test, MAX3, and logistic regression were applied to analyze the association between single nucleotide polymorphism (SNP) and T2DM; unconditional logistic regression was used to analyze haplotype in LD block; and SNP set analysis based on logistic kernel machine regression was used to analyze pathway. All statistical analysis was performed by SPSS25.0, R2.14, Haploview4.2, SNPStats, and other statistical software packages.

Results

In association analysis based on SNP, rs2167270 had statistical significance both in the adjusted and unadjusted covariate dominant model and in the unadjusted covariate overdominant model while it had no significant difference in the adjusted covariate overdominant model. Compared to GG genotype, rs2167270 of AG genotype had statistical significance in both the adjusted and unadjusted covariate codominant models. And rs16147 had statistical significance in robust test, stealth model and overdominant model, and adjusting and unadjusting covariate. This study found linkage disequilibrium existed between rs2167270 and rs4731426 of LEP, rs10889502 and rs17127107 of JAK1, rs2970847 and rs6821591 of PPARGC1A, rs249429 and rs3805486 of PRKAA1, rs1342382 and rs6588640 of PRKAA2, rs3766522 and rs6937 of PRKAB2, rs2970847 and rs6821591 of PRKAG2, and rs6436094 and rs645163 of PRKAG3. There was no positive finding with statistical significance from the unconditional logistic regression of the mentioned genes' haplotype of LD block.

Conclusions

LEP signaling pathway association with T2DM remained to be confirmed in Chinese Han population, although rs2167270 and rs16147 were significantly associated with T2DM.

One Year of Dapaglifozin Add-On Therapy Ameliorates Surrogate Indexes of Insulin Resistance and Adiposity in Patients with Type 2 Diabetes Mellitus

INTRODUCTION

This study investigates the effects of dapagliflozin on the visceral adiposity index (VAI), lipid accumulation product (LAP), product of triglycerides and glucose (TyG) and triglycerides to HDL-cholesterol ratio (TG/HDL-C) in patients with type 2 diabetes mellitus (T2D).

METHODS

In this real-life study, dapaglifozin was added to metformin alone (group 1, no. 42) or insulin plus metformin (group 2, no. 58) in 100 T2D patients.

RESULTS

In group 1, after 6 months of dapaglifozin addition, a significant decrease in BMI (p < 0.001), waist circumference (WC) (p < 0.001), systolic blood pressure (SBP) (p = 0.009), diastolic blood pressure (DBP) (p = 0.012), mean fasting blood glucose (FBG), post-breakfast glucose (PBG), post-lunch glucose (PLG) and post-dinner glucose (PDG) (all p < 0.001), HbA1c (p < 0.001), VAI (p = 0.020), LAP (p = 0.028), Tyg (p < 0.001), TG/HDL-C (p = 0.020) and glutamate pyruvate transaminase (GPT) (p < 0.001) was observed compared to baseline. After 12 months a significant decrease in BMI (p < 0.001), WC (p = 0.006), SBP (p = 0.023), DBP (p = 0.005), mean FPG, PBG, PLG and PDG (all p < 0.001), HbA1c (p < 0.001), total cholesterol (p = 0.038), triglycerides (p = 0.026), VAI (p = 0.013), GPT (p < 0.001), LAP index (p = 0.024), Tyg index (p < 0.001) and TG/HDL-c ratio (p = 0.016) was observed compared to baseline. In group 2, after 6 months of dapaglifozin addition, a significant decrease in BMI (p < 0.001), WC (p < 0.001), SBP (p = 0.015), DBP (p = 0.007), mean FPG, PBG, PLG and PDG (all p < 0.001), HbA1c (p < 0.001), VAI (p = 0.040), LAP (p = 0.047), Tyg (p < 0.001), TG/HDL-C (p = 0.048) and GPT (p < 0.001) was observed compared to baseline. By contrast, after 12 months a significant decrease in BMI (p < 0.001), WC (p < 0.001), SBP (p = 0.001), DBP (p = 0.002), mean FPG, PBG, PLG and PDG (all p < 0.001), HbA1c (p < 0.001), GPT (p < 0.001) and Tyg index (p = 0.003) was observed compared to baseline.

CONCLUSIONS

Dapagliflozin treatment significantly reduced surrogate indexes of insulin resistance and adiposity in patients with T2D.

Prediction of type 2 diabetes mellitus using noninvasive MRI quantitation of visceral abdominal adiposity tissue volume

Background

The correlation between visceral adipose tissue volume (VATV), hepatic proton-density fat fraction (PDFF), and pancreatic PDFF has been previously studied to predict the presence of type 2 diabetes mellitus (T2DM). This study investigated VATV quantitation in patients with T2DM, prediabetes, and normal glucose tolerance (NGT) using MRI to assess the roles of VATV, hepatic, and pancreatic PDFF in predicting the presence of T2DM.

Methods

Forty-eight patients with a new clinical diagnosis of T2DM (n=15), prediabetes (n=17), or NGT (n=16) were included and underwent abdominal magnetic resonance imaging (MRI) scanning with the iterative decomposition of water and fat with echo asymmetry and least square estimation image quantification (IDEAL-IQ) sequencing. VATV was obtained at the level of the 2^nd and 3^rd lumbar vertebral bodies (VATV L2 and VATV L3) where the sum of VATV L2 and VATV L3 (total VATV) were computed, respectively. Also, pancreatic and hepatic fat content was quantified by measuring the PDFF. The receiver operating characteristic (ROC) curve and binary logistics regression model analysis were employed to evaluate their ability to predict the presence of T2DM.

Results

The VATV L2, VATV L3, and total VATV values of the T2DM group were significantly higher than the prediabetes and NGT groups (P<0.05). There was no statistically significant difference between the values of VATV L2, VATV L3, and total VATV between the prediabetes and NGT groups (P>0.05). The ROC curve showed the areas under the curve for VATV L2, VATV L3, total VATV, hepatic PDFF, and pancreatic PDFF were 0.76, 0.80, 0.80, 0.79, and 0.75, respectively, in predicting the presence of T2DM (P<0.01). The ROC curves of VATV L2, VATV L3, total VATV, hepatic PDFF, and pancreatic PDFF failed to predict the presence of prediabetes and NGT (P>0.05). The binary logistics regression model analysis revealed that only VATV L3 was independently associated with the incidence of T2DM (P=0.01 and OR =1.01). The sensitivity, specificity, and total accuracy were 80.00%, 88.20%, and 84.40%, respectively.

Conclusions

Compared with hepatic PDFF, pancreatic PDFF, VAVT L2, and total VATV, VAVT L3 was the better predictor of T2DM.

Effects of different exercise modalities on novel hepatic steatosis indices in overweight women with type 2 diabetes

BACKGROUND/AIMS

Fatty liver is a clinical and pathologic condition in individuals with type 2 diabetes (T2D). The purpose of this study is to examine the effects of different exercise modalities on non-alcoholic fatty liver indices (fatty liver index [FLI], lipid accumulation product [LAP], hepatic steatosis index [HSI], and Framingham Steatosis Index [FSI]) in women with T2D.

METHODS

Fifty-two women with T2D and a mean age of 55.07±5.92 yrs, body mass index (BMI) 28.94±4.09 kg/m2 , and hemoglobin A1c (HbA1c) 9.41±0.82% were randomized to a sprint interval training (SIT) (n=17), combined aerobic and resistance (A+R) training (n=17), or control group (n=18) for 10 weeks. Two-way repeated analysis of variance (ANOVA) was used to find differences between groups and the effects of time and Time×Group interactions after 10 weeks on non-alcoholic fatty liver indices. After this, ANOVA models were constructed to determine the effects of group allocation and change in non-alcoholic fatty liver indices.

RESULTS

There were significant time interactions for FLI (P<0.001), HSI (P<0.001), and LAP (P<0.001). Also, there were significant Time×Group interactions for fasting blood glucose (P=0.034), and HbA1c (P=0.006).

CONCLUSION

Results highlight that exercise training, independent of mode of training, is an effective strategy to improve some indices related to hepatic steatosis and blood glucose profiles in women with T2D.

The impact of lipid accumulation product (LAP) and visceral adiposity index (VAI) on clinical, hormonal and metabolic parameters in lean women with polycystic ovary syndrome

This study was performed to assess the impact of lipid accumulation product (LAP) and visceral adiposity index (VAI) on clinical, hormonal, and metabolic parameters in lean women with PCOS. Retrospective analysis of 120 consecutive lean PCOS subjects was performed. Subjects were divided into two groups according to HOMA-IR, as IR + and IR-. A HOMA-IR value above 2.5 was used to indicate IR. Clinical, hormonal and metabolic parameters were compared between the two groups. Correlations between LAP and VAI and clinical, hormonal, metabolic features in women PCOS were analyzed. One hundred twenty lean PCOS subjects were enrolled, of which 39 were insulin resistant. Comparison of group means showed significantly higher values for TG levels, FAI, FGS, TG/HDL-c, TyG, LAP, and VAI indexes and lower values for glucose/insulin ratio and QUICKI in the IR + group. LAP and VAI were both found to be positively correlated with each other and with WC, FAI, FGS, TG, TC levels, lipid ratios, TyG index, and HOMA-IR and negatively correlated with Glucose/Insulin ratio, QUICKI, and HDL-c in lean women with PCOS. LAP and VAI may be promising in early identification of IR and cardiometabolic risk and may be useful for the assessment of hyperandrogenism in lean women with PCOS.

Relationships of surrogate indexes of insulin resistance with insulin sensitivity assessed by euglycemic hyperinsulinemic clamp and subclinical vascular damage

INTRODUCTION

Insulin resistance plays a crucial role in the pathogenesis of type 2 diabetes and cardiovascular disease. The triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio, visceral adiposity index (VAI), lipid accumulation product (LAP) and triglycerides × fasting glucose (TyG) index are surrogate measures of insulin sensitivity based on anthropometric and/or biochemical parameters routinely collected in clinical practice. Herein, we compared the relationships of these four surrogate indexes with insulin sensitivity assessed by the gold standard euglycemic hyperinsulinemic clamp technique, and subclinical vascular damage.

RESEARCH DESIGN AND METHODS

631 subjects with different degrees of glucose tolerance underwent euglycemic hyperinsulinemic clamp. The surrogate TG/HDL-C ratio, VAI, LAP and TyG indexes were computed. Pulse pressure and carotid intima-media thickness (IMT) were measured as indicators of subclinical vascular damage.

RESULTS

All the four surrogate indexes showed a significant correlation with insulin-stimulated glucose disposal in the whole study population. However, only LAP index had a significant association with insulin sensitivity across the different glucose tolerance groups. LAP index showed the highest area under the receiver operating characteristic curve (0.728) to detect individuals with insulin resistance defined as the bottom quartile of insulin-stimulated glucose disposal, followed by TG/HDL-C ratio (0.693), TyG index (0.688) and VAI (0.688). A significant association was found between the four indexes of insulin sensitivity and pulse pressure and IMT. All the four indexes have a similar ability to detect individuals with vascular atherosclerosis defined by IMT>0.9 mm. Conversely, LAP index had the greatest ability to recognize individuals with increased vascular stiffness defined by pulse pressure ≥60 mm Hg.

CONCLUSION

Among the surrogate TG/HDL-C ratio, VAI, LAP and TyG indexes of insulin sensitivity, LAP index showed a significant association with insulin-stimulated glucose disposal across the different glucose tolerance categories and the highest ability to detect insulin resistance and subclinical vascular damage.

Is Lipid Accumulation Product Associated with an Atherogenic Lipoprotein Profile in Brazilian Subjects?

Background

Lipid accumulation product (LAP), a simple and low-cost tool, is a novel biomarker of central lipid accumulation and represents a potential surrogate marker for atherogenic lipoprotein profile. However, its association with lipoprotein subfractions has not been described in the literature.

Objective

To determine whether LAP index could be used as a marker of low- and high-density lipoprotein (LDL and HDL) size in Brazilian individuals.

Methods

This cross-sectional study included patients (n = 351) of both sexes and age between 30-74 years. Clinical and sociodemographic data and family history of diseases were evaluated. Lipoprotein size, and levels of total cholesterol (TC), lipoproteins, apolipoprotein AI and B (APO AI/APO B), glucose, insulin, insulin resistance index (HOMA-IR) and non-esterified fatty acids (NEFA) were assessed in blood samples. LAP was calculated by the formulas [(waist circumference_[cm]-58) × (triglycerides_[mmol/L]) for women and (waist circumference _[cm]-65) × (triglycerides _[mmol/L]) for men]. The association between LAP and metabolic parameters were tested by linear trend (general linear model, GLM test) before and after multiple adjustments for potential confounders (sex, age, smoking, statin, fibrate, and hypoglycemic drugs) at significant level p < 0.05.

Results

LAP was positively associated with TC, APO B, NEFA, glucose, insulin and HOMA-IR values, and negatively associated with HDL-C. Higher central lipid accumulation was corelated with higher percentage of intermediate HDL and of small LDL and HDL and less amount of large HDL. LDL size was also reduced in greater LAP index values. The negative impact of LAP was maintained after adjustment for multiple variables.

Conclusion

LAP was robustly associated with atherogenic profile of lipoprotein subfractions, independently of multiple confounders.

Three novel obese indicators perform better in monitoring management of metabolic syndrome in type 2 diabetes

The present study evaluated the performance of three novel obese indicators, visceral adiposity index (VAI), lipid accumulation product (LAP) and waist circumference-triglyceride index (WTI), for identifying metabolic syndrome(MetS) in type 2 diabetes. A cross-sectional study was conducted on 711 type 2 diabetes in Qinhuangdao. The MetS was defined as the definition of Chinese Diabetes Society. Receiver operating characteristic curve analyses were performed to assess the accuracy of three obese indicators as diagnostic tests for MetS. The prevalence of MetS was 71.3%. In men, among all three obese indicators, the LAP had the highest area under curve (AUC) value (AUC = 0.894), followed by VAI (AUC = 0.860) and WTI (AUC = 0.855). In women, among all three obese indicators, the LAP had the highest AUC value (AUC = 0.906), followed by WTI (AUC = 0.887) and VAI (AUC = 0.881). However. there was no significant difference between the three obese indicators(P > 0.05). Three obese indicators were effective indicators for the screening of MetS, LAP and WTI are more simple.

Toll-like receptor-2 and -4 are associated with hyperlipidemia

Recent studies have suggested that toll-like receptors (TLRs) contribute to insulin resistance, and that fatty acids have a role in TLR activation. Other studies have found that TLR2 and TLR4 upregulation is consistent with an increase in serum lipid. Therefore, it was hypothesized that TLRs are associated with hyperlipidemia. The aim of the present study was to investigate whether TLR2 or TLR4 was associated with hyperlipidemia and to provide novel targets for hyperlipidemia therapy. Volunteers were selected at the Medical Examination Center of Hebei General Hospital (Shijiazhuang, China), including 43 patients with high triglyceride (TG) levels, 84 with high total cholesterol (TC) levels and 55 with high TG and high TC levels. In addition, 68 healthy volunteers were selected as a control group. For the animal study, the TLR gene and protein levels were assessed in the skeletal muscle of rats fed a high‑fat diet. As expected, TLR2 and TLR4 gene expression were upregulated when TC increased, TG increased, or TC and TG increased. In rats fed a high‑fat diet, the levels of gene and protein expression in the skeletal muscle of the two TLRs were all increased compared with the control group, this was consistent with an increase in TC and TG. In addition, in drug treatment groups the mRNA and protein expression levels of TLR in the skeletal muscle of rats fed a high fat diet were decreased, as were the TC and TG levels. In conclusion, these findings suggest that TLR2 and TLR4 are associated with hyperlipidemia.

Pathophysiology and treatment of diabetic retinopathy

In the past years, the management of diabetic retinopathy (DR) relied primarily on a good systemic control of diabetes mellitus, and as soon as the severity of the vascular lesions required further treatment, laser photocoagulation or vitreoretinal surgery was done to the patient. Currently, even if the intensive metabolic control is still mandatory, a variety of different clinical strategies could be offered to the patient. The recent advances in understanding the complex pathophysiology of DR allowed the physician to identify many cell types involved in the pathogenesis of DR and thus to develop new treatment approaches. Vasoactive and proinflammatory molecules, such as vascular endothelial growth factor (VEGF), play a key role in this multifactorial disease. Current properly designed trials, evaluating agents targeting VEGF or other mediators, showed benefits in the management of DR, especially when metabolic control is lacking. Other agents, directing to the processes of vasopermeability and angiogenesis, are under investigations, giving more hope in the future management of this still sight-threatening disease.

Expression of leptin and its long-form receptor in the marginal cutaneous tissues of diabetic foot ulcers

To investigate the relationship between the expression of leptin and its long-form receptor, OB-RL, and wound healing in diabetic foot ulcers. Biopsies from 10 patients with diabetic foot ulcers (DU group), 10 with non-diabetic foot ulcers (NDU group), and 10 with normal skin (normal control, NC group) were examined. Leptin and OB-RL mRNA and protein levels were assessed using RT-PCR and immunohistochemistry analyses, respectively. The cuticle thickness was significantly greater, and the epidermal layer was significantly lesser in the DU and NDU groups. Leptin protein expression was significantly higher in the DU and NDU than NC group (P < 0.001), whereas OB-RL mRNA and protein expressions were significantly lower in the DU group and significantly higher in the NDU group (P < 0.001). Diabetic foot ulcer duration was negatively correlated with OB-RL protein expression (ρ = -0.671, P = 0.034). Decreased OB-RL may result in reduced leptin signaling in diabetic foot ulcers. Further studies are required to determine whether OB-RL levels are related to the prognosis of diabetic foot ulcers, as well as to explore the use of leptin or mimetics for promoting ulcer healing.