Decreased in n-3 DHA enriched triacylglycerol in small extracellular vesicles of diabetic patients with cardiac dysfunction

PURPOSE

Diabetic cardiomyopathy is the leading cause of death in diabetic patients, and the mechanism by which factors other than hyperglycemia contribute to the development of diabetic cardiomyopathy is unknown. Serum small extracellular vesicles (sEVs) carry bioactive proteins or nuclei, which enter into remote tissues and modulate cell functions. However, in diabetic conditions, the changes of lipids carried by sEVs has not been identified. Our study aims to explore the changes of lipids in sEVs in diabetic patients with cardiovascular disease, we hope to provide new ideas for understanding the role of lipid metabolism in the pathogenesis of diabetic cardiomyopathy.

METHODS

SEVs samples derived from serum of health controls (Ctrl), diabetic patients without cardiovascular diseases (DM), and diabetic patients with cardiovascular diseases (DM-CAD) were used for lipidomics analysis. Because AC16 cells are also treated with those sEVs to confirm the entrance of cells and effects on insulin sensitivity, a lipidomics analysis on cells was also performed.

RESULTS AND CONCLUSIONS

In this study, we found that docosahexaenoic acid (DHA)-triacylglycerides of sEVs from serums of DM-CAD patients decreased significantly, and those sEVs could enter into AC16 cells and diminish insulin sensitivity. In addition, DHA-triacylglycerides were also decreased in cells treated with sEVs from DM-CAD. Therefore, DHA-triacylglycerides carried by sEVs may mediate intercellular signaling and be associated with the incidence of diabetic cardiovascular complications.

The link between obesity and insulin resistance among children: Effects of key metabolites

BACKGROUND

Childhood obesity became a severe public health challenge, and insulin resistance (IR) was one of the common complications. Both obesity and IR were considered as the basis of metabolic disorders. However, it is unclear which common key metabolites are associated with childhood obesity and IR.

METHODS

The children were divided into normal weight and overweight/obese groups. Fasting blood glucose and fasting insulin were measured, and homeostasis model assessment of insulin resistance was calculated. Liquid chromatography-tandem mass spectrometry was applied for metabonomic analysis. Multiple linear regression analysis and correlation analysis explored the relationships between obesity, IR, and metabolites. Random forests were used to rank the importance of differential metabolites, and relative operating characteristic curves were used for prediction.

RESULTS

A total of 88 normal-weight children and 171 obese/overweight children participated in the study. There was a significant difference between the two groups in 30 metabolites. Childhood obesity was significantly associated with 10 amino acid metabolites and 20 fatty acid metabolites. There were 12 metabolites significantly correlated with IR. The ranking of metabolites in random forest showed that glutamine, tyrosine, and alanine were important in amino acids, and pyruvic-ox-2, ethylmalonic-2, and phenyllactic-2 were important in fatty acids. The area under the curve of body mass index standard deviation  score (BMI-SDS) combined with key amino acid metabolites and fatty acid metabolites for predicting IR was 80.0% and 76.6%, respectively.

CONCLUSIONS

There are common key metabolites related to IR and obese children, and these key metabolites combined with BMI-SDS could effectively predict the risk of IR.

Beta-cell function in type 2 diabetes (T2DM): Can it be preserved or enhanced?

Type 2 diabetes (T2DM) is a complex metabolic disorder manifested by hyperglycemia, insulin resistance, and deteriorating beta-cell function. A way to prevent progression of the disease might be to enhance beta-cell function and insulin secretion. However, most previous studies examined beta-cell function while patients were using glycemia-lowering agents without an adequate period off medications (washout). In the present review we focus on studies with a washout period. We performed a literature search (2010 to June 2021) using beta-cell function and enhancement. The evidence shows that beta-cell function can be enhanced. Bariatric surgery and very low calorie diets show improvement in beta-cell function in many individuals. In addition, use of glucagon-like peptide-1 receptor agonists for prolonged periods (3 years or more) can also lead to improvement of beta-cell function. Further research is needed to understand the mechanisms leading to improved beta-cell function and identify agents that could enhance beta-cell function in patients with T2DM.

A Review of micro RNAs changes in T2DM in animals and humans

Type 2 diabetes mellitus (T2DM) and its associated complications have become a crucial public health concern in the world. According to the literature, chronic inflammation and the progression of T2DM have a close relationship. Accumulated evidence suggests that inflammation enhances the insulin secretion lost by islets of Langerhans and the resistance of target tissues to insulin action, which are two critical features in T2DM development. Based on recently highlighted research that plasma concentration of inflammatory mediators such as tumor necrosis factor α and interleukin-6 are elevated in insulin-resistant and T2DM, and it raises novel question marks about the processes causing inflammation in both situations. Over the past few decades, microRNAs (miRNAs), a class of short, noncoding RNA molecules, have been discovered to be involved in the regulation of inflammation, insulin resistance, and T2DM pathology. These noncoding RNAs are specifically comprised of RNA-induced silencing complexes and regulate the expression of specific protein-coding genes through various mechanisms. There is extending evidence that describes the expression profile of a special class of miRNA molecules altered during T2DM development. These modifications can be observed as potential biomarkers for the diagnosis of T2DM and related diseases. In this review study, after reviewing the possible mechanisms involved in T2DM pathophysiology, we update recent information on the miRNA roles in T2DM, inflammation, and insulin resistance.

The role of obstetrician-gynecologists and reproductive endocrinologists in the blood glucose management of polycystic ovary syndrome

Background: This study aimed to compare the differences between reproductive endocrinologists (Repro-Endo) and obstetricians-gynecologists (Ob-Gyn; non-reproductive medicine specialty) in diagnosing, evaluating, and treating PCOS women with insulin resistance (IR).Methods: Repro-Endo and Ob-Gyn in China participated in this survey, and their responses were analyzed using χ² tests, Fisher exact tests, and multivariable logistic regression analysis.Results: The study analyzed 2412 survey responses (92.3% OB-Gyn; 98.5% women). Physician's age, hospital grade, specialty, and the number of PCOS patients who visit the physicians, revealed that Repro-Endo participants were more likely to suggest an oral glucose tolerance test (OR, 1.727; 95% CI, 1.272-2.345) as their first choice than Ob-Gyn participants. The most common treatments for patients with PCOS were lifestyle modification (>95%) and metformin use (>80%). More Repro-Endo participants prescribed metformin at a dose of 1.5 g/day compared with OB-Gyn (46.5% vs. 23.5%), and more OB-Gyn participants reported being unclear about the appropriate dosage of metformin for patients with obesity and PCOS (12.5% vs. 1.6%).Conclusion: This survey identified knowledge gaps in metabolic screening for patients with IR and PCOS. Similarly, it highlights the need to improve IR management education for physicians caring for PCOS women.

The reproductive endocrine feature and conception outcome of women with unknown etiological menstrual cycle (36-45 days) with long follicular phase

OBJECTIVE

To explore the reproductive endocrine feature and conception outcome of women with unknown etiological long menstrual cycle (LMC) (36-45 days) with long follicular phase.

METHODS

In the cohort study, we included 80 women with unknown etiological long menstrual cycle of biphasic basal body temperature (BBT) lasting for 36-45 days and 87 controls with normal cycle of biphasic BBT into LMC group and NMC group, respectively. Serum hormone levels, fasting glucose, and insulin of participants were tested, and ovulation was observed by ultrasound. The conception outcome was followed up within 12 menstrual cycles.

RESULTS

In the LMC group, the rate of abnormality of HOMA-insulin resistance index (40.0% vs. 20.7%, p < .01), luteal phase defect (30.9% vs. 13.8%, p < .05) and abnormality of FSH/LH ratio (15.6% vs. 5.7%, p < .05) were all significantly higher, but the serum estradiol level on the day before ovulation (261.10 pg/mL vs. 320.26 pg/mL, p < .01) was lower. The rate of poor ovulation quality (31.3% vs.15.4%, p < .05) in the LMC group was significantly higher than the NMC group. In the LMC group, the natural conception rate within 12 menstrual cycles was lower (41.9% vs. 66.2%, p < .01), whereas the spontaneous abortion rate in early pregnancy (29.0% vs. 9.8%, p < .05) and the conversion rate (21.6% vs. 5.2%, p < .01) to anovulation within 12 cycles were significantly higher.

CONCLUSIONS

Women with unknown etiological menstrual cycle (36-45 days) with long follicular phase have greater endocrine abnormality and higher risk of spontaneous abortion, infertility, and conversion to anovulation. Moderate early intervention may be advisable for these women, especially those who wish to get pregnant.

Bone morphogenetic protein-9 maybe an important factor which improves insulin resistance in PCOS

BACKGROUND

Polycystic ovary syndrome (PCOS) is closely related to insulin resistance (IR). Bone morphogenetic protein-9 (BMP-9) plays an important role in maintaining glucose homeostasis, but an association between BMP-9 and PCOS has not been reported. Here, we report the changes in BMP-9 and the influence of this protein on IR in PCOS.

METHODS

57 PCOS patients were selected (among them 25 received interventional treatment with exenatide (EX) for 3 months, and 32 received no treatment). 22 normal control individuals and 30 IR patients were also recruited. We evaluated IR with the euglycaemic-hyperinsulinaemic clamp (EHC) technique. IR and the glucose metabolism rate were assessed by EHC and [3-3H]glucose tracer experiments. We determined the protein expression levels of BMP-9, p-AKT (protein kinase B) and androgen receptor in the ovaries and liver by Western blotting.

RESULTS

We found that circulating BMP-9 levels were significantly decreased in PCOS with IR patients. Circulating BMP-9 levels and p-AKT levels were decreased in HFD and PCOS rats and increased after MF and EX treatment. The glucose infusion rate, glucose disappearance rate and suppression of hepatic glucose production decreased in the HFD and PCOS groups, the opposite results were found for HGP. AR protein expression levels increased in the HFD and PCOS groups and decreased in the MF and EX groups.

CONCLUSIONS

Our study results suggest that BMP-9 is an independent factor that influences IR in PCOS patients. The decrease in BMP-9 levels in the liver and ovaries may be involved in IR through the PI3K/AKT signaling pathway in PCOS rats.

Interleukin-15 are associated with insulin resistance in postmenopausal women with metabolic syndrome

OBJECTIVE

To determine if higher levels of circulating interleukin (IL)-15 are positively associated with improvement in insulin resistance in postmenopausal women (PW) with metabolic syndrome (MS).

METHODS

According to the median value of IL-15 at baseline, PW older than or equal to 45 years were divided into two groups: higher (n = 43) and lower (n = 42) IL-15. There was a 9-month follow-up period with clinical assessments at baseline and at 9 months (criteria of metabolic syndrome, body fat, and insulin resistance). Insulin resistance (IR) was calculated according to the Homeostasis Model Assessment-estimated insulin resistance (HOMA-IR). For IL-1β, IL-6, IL-10, IL-13, IL-33, IL-15, and TNF-α was determined using immunoassay Magnetic Bead Panel.

RESULTS

There was an interaction between the time and group only for insulin (p = .008) and HOMA-IR (p = .024). After adjusting for confounding variables (clinical and ILs), the HOMA-IR (p = .006) and insulin (p = .003) were lower in the higher-IL-15 group [HOMA-IR: 2.2 (95% CI: 1.9-2.5) and insulin: 9.1 µIU/mL (95% CI: 7.9-10.3)] when compared to the lower-IL-15 group [HOMA-IR: 3.1 (95% CI: 2.6-3.6) and insulin: 12.9 (95% CI: 11.1-14.9)] after 9 months of follow-up.

CONCLUSION

Higher levels of circulating IL-15 are positively associated with improvements in IR in PW with MS.

Ceramide changes in abdominal subcutaneous and visceral adipose tissue among diabetic and nondiabetic patients

BACKGROUND

This study profiles ceramides extracted from visceral and subcutaneous adipose tissue of human subjects by liquid chromatography-mass spectrometry to determine a correlation with status of diabetes and gender.

METHODS

Samples of visceral and abdominal wall subcutaneous adipose tissue (n = 36 and n = 31, respectively) were taken during laparoscopic surgery from 36 patients (14 nondiabetic, 22 diabetic and prediabetic) undergoing bariatric surgery with a body mass index (BMI) >35 kg/m² with ≥1 existing comorbidity or BMI ≥40 kg/m² . Sphingolipids were extracted and analyzed using liquid chromatography-mass spectrometry.

RESULTS

After logarithm 2 conversion, paired analysis of visceral to subcutaneous tissue showed differential accumulation of Cer(d18:1/16:0), Cer(d18:1/18:0), and Cer(d18:1/24:1) in visceral tissue of prediabetic/diabetic female subjects, but not in males. Within-tissue analysis showed higher mean levels of ceramide species linked to insulin resistance, such as Cer(d18:1/18:0) and Cer(d18:1/16:0), in visceral tissue of prediabetic/diabetic patients compared with nondiabetic subjects and higher content of Cer(d18:1/14:0) in subcutaneous tissue of insulin-resistant female patients compared with prediabetic/diabetic males. Statistically significant differences in mean levels of ceramide species between insulin-resistant African American and insulin-resistant Caucasian patients were not evident in visceral or subcutaneous tissue.

CONCLUSIONS

Analysis of ceramides is important for developing a better understanding of biological processes underlying type 2 diabetes, metabolic syndrome, and obesity. Knowledge of the accumulated ceramides/dihydroceramides may reflect on the prelipolytic state that leads the lipotoxic phase of insulin resistance and may shed light on the predisposition to insulin resistance by gender.

Vitamin D receptor methylation attenuates the association between physical activity and type 2 diabetes mellitus: A case-control study

BACKGROUND

Physical activity and vitamin D receptor (VDR) have been associated with type 2 diabetes mellitus (T2DM). However, the associations of VDR methylation with T2DM and physical activity remained unknown. We aimed to investigate whether VDR methylation was a link between physical activity and T2DM.

METHODS

A 1:1 matching case-control study was designed based on the Henan Rural Cohort Study, including 272 pairs of T2DM patients and nonpatients. Physical activity level was assessed using the International Physical Activity Questionnaire. The high-resolution melt method was applied to determine the methylation level of the promoter region of VDR. The association between physical activity and T2DM was analyzed with a conditional logistic regression model. The effect modification of VDR methylation levels on the association between physical activity and T2DM was conducted. A multivariate correlation analysis model was applied to investigate correlations of VDR methylation with insulin sensitivity.

RESULTS

Physical activity level was associated with T2DM risk (crude model: odds ratio [OR] 0.611; 95% CI, 0.416-0.897; adjusted model: OR 0.619; 95% CI, 0.418-0.917). In effect modification analysis, the effects of physical activity on T2DM were stronger for low VDR methylation levels than for high (P = .025). Moreover, VDR methylation levels were associated with insulin (r = -0.089, P = .039) as well as homeostatic model assessment of insulin resistance (r = -0.098, P = .022).

CONCLUSIONS

The methylation status of the VDR promoter is associated with the secretion and sensitivity of insulin. VDR methylation attenuates the association between physical activity and T2DM, indicating that proactively physical activity may reduce the risk of T2DM, especially in people with low VDR methylation level.

Clinical and biochemical characteristics of postpancreatitis diabetes mellitus: A cross-sectional study from the Danish nationwide DD2 cohort

BACKGROUND

Postpancreatitis diabetes mellitus (PPDM) is a common metabolic sequalae of acute and chronic pancreatitis. We conducted a cross-sectional study to examine the proportion of PPDM among patients clinically diagnosed with type 2 diabetes (T2D) in Denmark and their clinical and biochemical characteristics.

METHODS

We identified all past diagnoses of pancreatitis among patients in the Danish Centre for Strategic Research in Type 2 Diabetes (DD2) cohort through linkage with national health registries. Using International Classification of Diseases, Tenth Revision codes we categorized patients as PPDM and further divided them into acute/chronic subtypes (PPDM-A and PPDM-C). We assessed PPDM prevalence and examined associations with clinical and biochemical parameters using log binomial or Poisson regression to calculate age-/sex-adjusted prevalence ratios (aPRs).

RESULTS

Among 5564 patients with a clinical diagnosis of T2D, 78 (1.4%) had PPDM. Compared to T2D, PPDM patients were more often underweight or normal weight (body mass index ≤25.0 kg/m² : aPR 2.3; 95% confidence interval [CI]: 1.6-3.2) and had lower waist-to-hip ratio (≤0.95/≤0.80 in men/women: aPRs 1.8; 95% CI: 1.2-2.7). PPDM patients had lower plasma amylase levels (<17 U/L: aPRs 2.2; 95% CI: 1.1-4.3), higher insulin sensitivity (homeostatic model assessment 2S [HOMA2S] >63: aPR 2.0; 95% CI: 1.2-3.2) and tended to have worse glycaemic control (HbA1c ≥8.0%: aPRs 1.4; 95% CI: 0.8-2.4). PPDM-A was largely indistinguishable from T2D, whereas PPDM-C had impaired insulin secretion, higher insulin sensitivity, and worse glycemic control.

CONCLUSIONS

The proportion of PPDM among patients with clinically diagnosed T2D is ~1.5% in an everyday clinical care setting. Glucose metabolism of PPDM-A is largely indistinguishable from T2D, whereas PPDM-C differs in relation to insulin secretion and sensitivity.

Urinary C-peptide/creatinine ratio: A useful biomarker of insulin resistance and refined classification of type 2 diabetes mellitus

BACKGROUND

The urinary C-peptide/creatinine ratio (UCPCR) is low in patients with type 1 diabetes mellitus, but it has not been well characterized in patients with type 2 diabetes mellitus (T2DM). We aimed to measure the UCPCRs in patients with T2DM and explore the relationships among UCPCR, insulin resistance (IR), and chronic vascular complications of diabetes.

METHODS

A cross-sectional study was performed of 1299 Chinese hospitalized patients with T2DM. Binary logistic regression was used to evaluate the relationships between the chronic vascular complications of diabetes and UCPCR. K-means analysis was used to allocate participants to subgroups with five to six variables (age at diagnosis, body mass index [BMI], glycosylated hemoglobin, homoeostasis model assessment 2-estimated beta-cell function (HOMA2-B), and HOMA2-insulin resistance (HOMA2-IR), with or without UCPCR).

RESULTS

UCPCR positively correlated with HOMA2-IR (r = 0.448, P < .001). After adjustment for sex, age, duration of diabetes, and other cardiovascular risk factors, UCPCR was positively associated with diabetic kidney disease (DKD) (odds ratio [OR] = 1.198, 95% CI 1.019-1.408, P = .029) and coronary heart disease (CHD) (OR = 1.312, 95% CI 1.079-1.594, P = .006). When UCPCR was added, cluster analysis using the six variables identified five subgroups of T2DM, characterized by differing age at diagnosis, BMI, beta-cell function, IR, and prevalence of vascular complications.

CONCLUSIONS

UCPCR is positively associated with IR, DKD, and CHD and represents a promising biomarker that could refine the classification of T2DM.

Lower free thyroid hormone levels are associated with high blood glucose and insulin resistance; these normalize with metabolic improvement of type 2 diabetes

OBJECTIVE

This study aimed to explore the relationship of thyroid function and glucose metabolism and to investigate the changes in thyroid function after National Metabolic Management Center (MMC) management in type 2 diabetic mellitus (T2DM).

METHODS

A total of 2000 euthyroid participants from MMC in Shanghai General Hospital and a community physical examination were recruited. They were categorized into four groups: normal glucose tolerance (NGT, n = 132), prediabetes (N = 147), DM well-controlled (T2DM with glycosylated hemoglobin [HbA1c] ≤ 7%, n = 505), and DM uncontrolled (T2DM with HbA1c > 7%, n = 1216). The parameters were compared among the groups and their changes before and after MMC follow-up in DM uncontrolled group were observed.

RESULTS

Free triiodothyronine (FT3) and free thyroxine (FT4) levels varied significantly among groups. FT3 and FT4 levels negatively correlated with HbA1c level (P < 0.05), and positively correlated with the estimated glucose disposal rate (eGDR) (P < 0.05). Following MMC management, blood glucose and insulin resistance in the DM uncontrolled group were dramatically improved (P < 0.001). Meanwhile, FT3 was elevated compared to the baseline (from 4.51 ± 0.78 pmol/L to 4.68 ± 0.87 pmol/L, P < 0.05), and reverse triiodothyronine (r-T3) decreased from 1.03 ± 0.24 nmol/L to 0.92 ± 0.25 nmol/L (P < 0.001). Thyroid-stimulating hormone significantly decreased as well (P < 0.001).

CONCLUSIONS

Decreased free thyroid hormone levels in normal range were associated with high glucose and insulin resistance. After MMC management, improvement of blood glucose and insulin resistance were accompanied by the restoration of low-normal thyroid function.

Association of circulating galectin-3 with gestational diabetes mellitus, progesterone, and insulin resistance

BACKGROUND/OBJECTIVE

Because galectin-3 has been proposed to regulate obesity and insulin resistance in mice, we hypothesized that circulating galectin-3 levels are associated with presence of gestational diabetes mellitus (GDM), progesterone, and insulin resistance.

METHODS

Circulating galectin-3 levels were measured using an enzyme-linked immunosorbent assay (ELISA) in women with GDM (n = 137) and their controls (n = 81). Associations of galectin-3 and progesterone with GDM and insulin resistance were evaluated using regression models.

RESULTS

Circulating galectin-3 levels were increased in the individuals with GDM (P < .001) and associated significantly with progesterone (r = 0.42, P < .001), gestational age at sampling (r = 0.23, P < .001), current body mass index (BMI; r = 0.17, P = .02), estrogen (r = 0.15, P < .03), fasting glucose (r = 0.41, P < .001), fasting insulin (r = 0.39, P < .001), and homeostasis model assessment of insulin resistance (HOMA-IR; r = 0.44, P < .001). After adjustment for potential confounders, including current BMI, subjects in the highest tertile of galectin-3 levels were more likely to have GDM (odds ratio 4.71, 95% confidence interval 2.01-11.06) as compared with the lowest tertile. The association between circulating galectin-3 levels and GDM remained significant after adjusting for progesterone, but significantly attenuated after adjustment with HOMA-IR. Furthermore, the multiple linear regression analyses after adjustment for confounders showed an independent association between galectin-3 levels and HOMA-IR (β = .41, P < .001), suggesting that association of circulating gelactin-3 levels with GDM might be mediated via insulin resistance. Progesterone demonstrated the expected associations with galectin-3, GDM, and HOMA-IR.

CONCLUSIONS

Circulating galectin-3 levels are associated with GDM possibly through increased insulin resistance. The association of galectin-3 with progesterone highlights a potential role of progesterone in its interaction with galectin-3.

Factors leading to high morbidity and mortality of COVID-19 in patients with type 2 diabetes

Coronavirus disease 2019 (COVID-19) is a recent pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus. Diabetes (mostly type 2 diabetes mellitus, T2DM) and hyperglycemia are among the major comorbidities in patients with COVID-19 leading to poor outcomes. Reports show that patients with diabetes and COVID-19 are at an increased risk for developing severe complications including acute respiratory distress syndrome, multi-organ failure, and death. Here we explore potential mechanistic links that could explain the observed higher morbidity and mortality in this patient population. Patients with T2DM have an underlying increased level of inflammation associated with obesity and insulin resistance in addition to other comorbidities including hypertension, obesity, cardiovascular disease, dyslipidemia, and being older. We review evidence that T2DM with hyperglycemia are among factors that lead to elevated expression of angiotensin-converting enzyme 2 (ACE2) in lungs and other tissues; ACE2 is the cellular "receptor" and port of viral entry. The preexisting chronic inflammation with augmented inflammatory response to the infection and the increasing viral load leads to extreme systemic immune response ("cytokine storm") that is strongly associated with increased severity of COVID-19. Based on the available evidence, it is recommended by a panel of experts that safe but stringent control of blood glucose, blood pressure, and lipids be carried out in patients with T2DM, measures that could potentially serve to decrease the severity of COVID-19 should these patients contract the viral infection. Once the infection occurs, then attention should be directed to proper glycemic control with use of insulin and frequent monitoring of blood glucose levels.

GLP-1 and insulin regulation of skeletal and cardiac muscle microvascular perfusion in type 2 diabetes

Muscle microvasculature critically regulates skeletal and cardiac muscle health and function. It provides endothelial surface area for substrate exchange between the plasma compartment and the muscle interstitium. Insulin fine-tunes muscle microvascular perfusion to regulate its own action in muscle and oxygen and nutrient supplies to muscle. Specifically, insulin increases muscle microvascular perfusion, which results in increased delivery of insulin to the capillaries that bathe the muscle cells and then facilitate its own transendothelial transport to reach the muscle interstitium. In type 2 diabetes, muscle microvascular responses to insulin are blunted and there is capillary rarefaction. Both loss of capillary density and decreased insulin-mediated capillary recruitment contribute to a decreased endothelial surface area available for substrate exchange. Vasculature expresses abundant glucagon-like peptide 1 (GLP-1) receptors. GLP-1, in addition to its well-characterized glycemic actions, improves endothelial function, increases muscle microvascular perfusion, and stimulates angiogenesis. Importantly, these actions are preserved in the insulin resistant states. Thus, treatment of insulin resistant patients with GLP-1 receptor agonists may improve skeletal and cardiac muscle microvascular perfusion and increase muscle capillarization, leading to improved delivery of oxygen, nutrients, and hormones such as insulin to the myocytes. These actions of GLP-1 impact skeletal and cardiac muscle function and systems biology such as functional exercise capacity. Preclinical studies and clinical trials involving the use of GLP-1 receptor agonists have shown salutary cardiovascular effects and improved cardiovascular outcomes in type 2 diabetes mellitus. Future studies should further examine the different roles of GLP-1 in cardiac as well as skeletal muscle function.

[Effect of breastfeeding on insulin sensitivity in infants with intrauterine growth retardation: a follow-up study]

OBJECTIVE

To study insulin sensitivity and the serum level of adiponectin in infants with intrauterine growth retardation (IUGR) and the effect of breastfeeding on the insulin sensitivity through a follow-up study.

METHODS

A total of 106 full-term IUGR infants who were hospitalized from October 2014 to October 2018 were enrolled as the IUGR group, and 90 full-term appropriate for gestational age (AGA) infants who were born during the same period of time were enrolled as the AGA group. Birth weight and body length were recorded. Serum levels of fasting blood glucose (FBG), triglyceride (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), insulin, and adiponectin were measured on day 7 after birth. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. According to the feeding pattern, the IUGR group was further divided into a breastfeeding group with 37 infants and a formula feeding group with 42 infants. The above serum indices and growth indices were also measured at the age of 3 and 6 months.

RESULTS

Compared with the AGA group, the IUGR group had significantly increased levels in serum insulin and HOMA-IR and a significantly decreased level of adiponectin (P<0.05). There were no significant differences between the breastfeeding and formula feeding groups in growth indices and serum levels of FBG, TG, LDL, and HDL on day 7 after birth and at the ages of 3 and 6 months (P>0.05). In the breastfeeding group, serum insulin and HOMA-IR decreased and adiponectin level increased over the time of breastfeeding (P<0.05).

CONCLUSIONS

Insulin sensitivity decreases in the early stage after birth in IUGR infants, and breastfeeding can improve insulin sensitivity.

Increasing insulin resistance predicts adverse pregnancy outcomes in women with gestational diabetes mellitus

BACKGROUND

This study aimed to investigate the association between maternal insulin resistance (IR) in the late second trimester and pregnancy outcomes, as well as to identify risk factors of IR among women with gestational diabetes mellitus (GDM).

METHODS

A retrospective study was conducted among 2647 women diagnosed with GDM. IR was evaluated using the homeostasis model assessment method for IR (HOMA-IR) in the late second trimester (between 24 and 28 weeks), and the lipid profiles were measured at the same time. Patients were divided into groups based on quartiles of HOMA-IR. The information on pregnancy outcomes and risk factors was extracted from the medical records of all participants and entered electronically. Logistic regression models were used to analyze the associations between HOMA-IR and pregnancy outcomes, as well as the associations between risk factors and HOMA-IR.

RESULTS

Greater IR was associated with cesarean delivery, preterm delivery, macrosomia, and large for gestational age newborns, but only significantly associated with preterm delivery after adjustment for potential confounders (P < .001). Prepregnancy body mass index (BMI), weight gain before diagnosis of GDM, and triglycerides were significantly related with IR in the late second trimester (P < .001). Besides, the total area under the curve of the diagnostic 75-g oral glucose tolerance test and glycosylated hemoglobin A1c increased from the lowest to the highest HOMA-IR groups.

CONCLUSIONS

Increasing IR in the late second trimester predicts adverse pregnancy outcomes especially for preterm delivery in women with GDM. Additionally, prepregnancy BMI and weight gain before diagnosis of GDM are independent risk factors for the development of IR.

Increased urocortin 3 levels are associated with the risk of having type 2 diabetes mellitus

BACKGROUND

Urocortin 3 (UCN3) is a peptide hormone playing a pivotal role in glucose and lipid metabolisms. However, its clinical implications remain unclear. Our aims were to investigate the altered levels of UCN3 in newly diagnosed type 2 diabetes mellitus (nT2DM) patients in comparison to subjects with normal glucose tolerance (NGT) and to determine the presence of any possible link between UCN3 levels and metabolic parameters.

METHODS

Eighty nT2DM and 80 age-, body mass index (BMI)-, and gender-matched NGT subjects were enrolled into this case-control study. The circulating UCN3 levels were measured using the enzyme-linked immunoabsorbent assay (ELISA). Metabolic parameters of enrolled subjects were also determined. A standard 75-g 2-hour oral glucose tolerance test was used for diagnosis of type 2 diabetes mellitus (T2DM).

RESULTS

UCN3 levels were higher in subjects with nT2DM than in controls (115.64 ± 39.26 vs 86.16 ± 22.81 pg/mL, P < .001). UCN3 levels were increased in subjects with metabolic syndrome compared to subjects without metabolic syndrome in both nT2DM and NGT groups. UCN3 levels showed a positive correlation with BMI in both groups. Moreover, UCN3 levels were positively and independently associated with insulin, fasting blood glucose, insulin resistance, 2-hour plasma glucose, glycosylated hemoglobin, and triglycerides, whereas UCN3 levels were negatively and independently associated with high-density lipoprotein cholesterol. According to logistic regression analysis, increased risk of T2DM and metabolic syndrome were parallel with the highest elevated levels of UCN3.

CONCLUSIONS

Increased levels of UCN3 are associated with unfavorable metabolic profiles in T2DM, indicating a potential role of UCN3 in glucose and lipid metabolisms in T2DM.

Insulin resistance is associated with urinary albumin-creatinine ratio in normal weight individuals with hypertension and diabetes: The REACTION study

BACKGROUND

The relationship between albuminuria and insulin resistance (IR) has not been clarified in previous studies. This study was conducted to examine whether IR is associated with albuminuria in subjects with diverse blood pressure and glycometabolism statuses.

METHODS

This study included 34 136 participants whose data were drawn from a cross-sectional survey named the 2011 REACTION study. The participants were divided into six groups. The urinary albumin-creatinine ratio (UACR) and glomerular filtration rate (GFR) were used as markers of chronic kidney disease (CKD). Variance tests and logistic regression models were performed for homeostatic model assessment of insulin resistance (HOMA-IR) in relation to UACR and eGFR.

RESULTS

First, UACR levels and HOMA-IR exhibited a positive correlation among participants (P < 0.05), and a negative correlation existed between GFR and HOMA-IR (P < 0.05). Second, in the hypertension with diabetes group, in individuals whose body mass index (BMI) was 18.5-24.0 kg/m² , age was 50-60 years old, low density lipoprotein cholesterol (LDL-C) was 2.6-3.4 mmol/L or high density lipoprotein cholesterol (HDL-C) was 0.9-1.55 mmol/L, HOMA-IR was positively associated with UACR (P < 0.05). However, there was a negative correlation between GFR and HOMA-IR in the hypertension with diabetes group in individuals whose BMI was 18.5-24.0 kg/m² or whose age was over 65 years old (P < 0.05).

CONCLUSIONS

In the context of different blood pressure and glycometabolism statuses, the positive correlation between UACR levels and HOMA-IR was affected by BMI, age, LDL-C, HDL-C, and GFR. In patients with hypertension and diabetes, the early detection and intervention of IR and related risk factors in patients with normal BMI may reduce the occurrence of microalbuminuria and delay the progression of CKD.

[Associations of impaired glucose metabolism with chronic peridontitis in pre-diabetes patients]

OBJECTIVE

To investigate the associations of impaired glucose metabolism and insulin resistance with chronic periodontitis in pre-diabetes patients.

METHODS

A cross-sectional analysis was conducted and we included a total of 171 pre-diabetes patients aged 30-65 years, free of diabetes. pre-diabetes was defined as impaired fasting glucose (IFG) [fasting glucose (FG): 6.1-7.0 mmol/L] and/or impaired glucose tolerance (IGT) [oral glucose tolerance test (OGTT): 7.8-11.0 mmol/L]. Chronic periodontitis was defined according to Centers for Disease Control and Prevention (CDC)/American Academy of Periodontology (AAP) definition and the patients were divided into mild, moderate, and severe chronic periodontitis groups [mild: at least two interproximal sites with clinical attachment loss (CAL) ≥3 mm and at least two interproxima sites with probing depth (PD) ≥4 mm or 1 site with PD≥5 mm; moderate: at least two interproximal sites with CAL ≥4 mm and at least two interproxima sites with at least two interproximal sites with PD ≥5 mm; severe: at least two interproximal sites with CAL ≥6 mm and at least one interproxima site with at least two interproximal sites with PD≥5 mm]. A periodontal examination indexes [plaque index (PLI), PD, CAL, and bleeding on probing (BOP)] and glucose metabolism indexes [FG, OGTT, hemoglobinA1c (HbA1c), fasting insulin and homeostasis model assessments of insulin resistance (HOMA-IR)] were measured. The association of glucose metabolism and chronic periodontitis was investigated by multivariable logistic regression analysis.

RESULTS

FG in the moderate and severe chronic periodontitis groups was significantly higher compared with mild chronic periodontitis group, HOMA-IR in the moderate and severe chronic periodontitis groups was significantly higher compared with mild chronic periodontitis group, OGTT in the severe chronic periodntitis group was significantly higher compared with mild chronic peridontitis group and moderate chronic periodontitis groups, and there was no significant difference between moderate and mild chronic periodontitis groups. For the insulin and HbA1c, there was no significant difference among mild, moderate and severe chronic periodontitis groups. After multivariable adjustment of age, gender, smoking status, hypertension and body mass index, IFG (OR=1.39, 95%CI: 1.01-1.98) and HOMA-IR (OR=1.36, 95%CI: 1.04-1.76) were associated with moderate periodontitis; IFG (OR=1.64, 95%CI: 1.17-2.40), IGT (OR=1.65, 95%CI: 1.21-2.26), and HOMA-IR (OR=1.72, 95%CI: 1.23-2.41) were significantly associated with severe periodontitis.

CONCLUSION

Our data provided evidences that impaired glucose metabolism were associated with chronic periodontitis among pre-diabetes patients.

[Associations of impaired glucose metabolism with chronic peridontitis in pre-diabetes patients]

OBJECTIVE

To investigate the associations of impaired glucose metabolism and insulin resistance with chronic periodontitis in pre-diabetes patients.

METHODS

A cross-sectional analysis was conducted and we included a total of 171 pre-diabetes patients aged 30-65 years, free of diabetes. pre-diabetes was defined as impaired fasting glucose (IFG) [fasting glucose (FG): 6.1-7.0 mmol/L] and/or impaired glucose tolerance (IGT) [oral glucose tolerance test (OGTT): 7.8-11.0 mmol/L]. Chronic periodontitis was defined according to Centers for Disease Control and Prevention (CDC)/American Academy of Periodontology (AAP) definition and the patients were divided into mild, moderate, and severe chronic periodontitis groups [mild: at least two interproximal sites with clinical attachment loss (CAL) ≥3 mm and at least two interproxima sites with probing depth (PD) ≥4 mm or 1 site with PD≥5 mm; moderate: at least two interproximal sites with CAL ≥4 mm and at least two interproxima sites with at least two interproximal sites with PD ≥5 mm; severe: at least two interproximal sites with CAL ≥6 mm and at least one interproxima site with at least two interproximal sites with PD≥5 mm]. A periodontal examination indexes [plaque index (PLI), PD, CAL, and bleeding on probing (BOP)] and glucose metabolism indexes [FG, OGTT, hemoglobinA1c (HbA1c), fasting insulin and homeostasis model assessments of insulin resistance (HOMA-IR)] were measured. The association of glucose metabolism and chronic periodontitis was investigated by multivariable logistic regression analysis.

RESULTS

FG in the moderate and severe chronic periodontitis groups was significantly higher compared with mild chronic periodontitis group, HOMA-IR in the moderate and severe chronic periodontitis groups was significantly higher compared with mild chronic periodontitis group, OGTT in the severe chronic periodntitis group was significantly higher compared with mild chronic peridontitis group and moderate chronic periodontitis groups, and there was no significant difference between moderate and mild chronic periodontitis groups. For the insulin and HbA1c, there was no significant difference among mild, moderate and severe chronic periodontitis groups. After multivariable adjustment of age, gender, smoking status, hypertension and body mass index, IFG (OR=1.39, 95%CI: 1.01-1.98) and HOMA-IR (OR=1.36, 95%CI: 1.04-1.76) were associated with moderate periodontitis; IFG (OR=1.64, 95%CI: 1.17-2.40), IGT (OR=1.65, 95%CI: 1.21-2.26), and HOMA-IR (OR=1.72, 95%CI: 1.23-2.41) were significantly associated with severe periodontitis.

CONCLUSION

Our data provided evidences that impaired glucose metabolism were associated with chronic periodontitis among pre-diabetes patients.

Lifetime marijuana use in relation to insulin resistance in lean, overweight, and obese US adults

BACKGROUND

Obese individuals are more likely to show insulin resistance (IR). However, limited population studies on marijuana use with markers of IR have yielded mixed results. The aim of this study was to examine the association of marijuana use with IR in US adults with different body mass index (BMI) status.

METHODS

Data from the 2009 to 2016 National Health and Nutrition Examination Survey (NHANES) were abstracted. Minimal lifetime marijuana use was estimated using the duration of regular exposure and frequency of use. The association of marijuana use with both fasting insulin (FINS) and homeostasis model assessment of insulin resistance (HOMA-IR) was determined in lean, overweight, and obese individuals separately using generalized linear models. Interview weight years of data were used to account for the unequal probability of sampling and non-response.

RESULTS

Of all 129 509 adults aged 18 to 59 years, 50.3% were women. In current obese marijuana consumers, mean FINS in those with less than four uses per month was 52% (95% confidence interval [CI] 19%-71%) lower than in never users. In former obese consumers with eight or more uses per month and who stopped marijuana use <12 months ago, mean FINS was 47% (95% CI 18%-66%) lower than in never users. Mean FINS in those who quit marijuana 12 to 119 and 120 months and more prior the survey was 36% (95% CI 7%-57%) and 36% (95% CI 10%-54%) lower, respectively.

CONCLUSIONS

Marijuana use is associated with lower FINS and HOMA-IR in obese but not non-obese adults, even at low frequency of less than four uses per month. Former marijuana consumers with high lifetime use had significantly lower FINS levels that persisted, independent of the duration of time since last use.

[Level of circulating Alarin in obese children and its association with insulin resistance]

OBJECTIVE

To study the level of circulating Alarin in obese children and its association with various metabolic parameters.

METHODS

A total of 86 obese children with a body mass index (BMI) above the 95th percentile were enrolled as the obesity group, and 82 healthy children, matched for age and sex, with a BMI below the 85th percentile were enrolled as the healthy control group. According to the presence or absence of insulin resistance (IR), the obesity group was further divided into an IR group with 27 children and a non-IR group with 59 children. Related anthropometric parameters, including body height, body weight, systolic blood pressure (SBP), and diastolic blood pressure (DBP), were measured, and BMI was calculated. Total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), uric acid (UA), fasting insulin (FINS), and fasting blood glucose (FBG) were measured. The area under the receiver operating characteristic curve (AUC) for glucose and insulin, Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), and whole-body insulin sensitivity index (WBISI) were calculated. ELISA was used to measure the level of circulating Alarin.

RESULTS

The obesity group had a significantly higher level of circulating Alarin than the healthy control group (P<0.01). The IR group had a significantly higher level of circulating Alarin than the non-IR group (P<0.01). Circulating Alarin was positively correlated with BMI, TG, FBG, AUC-glucose, AUC-FINS, and HOMA-IR (P<0.05) and was negatively correlated with WBISI (P<0.05). The circulating Alarin level had a linear regression relationship with BMI, FBG, and HOMA-IR, among which HOMA-IR had the greatest influence on the circulating Alarin level (P<0.05).

CONCLUSIONS

There is a significant increase in the circulating Alarin level in obese children, which may be associated with the development of obesity and IR.

[Correlation between serum microRNA-122 and insulin resistance in obese children]

OBJECTIVE

To study the relationship between serum microRNA-122 (miR-122) and insulin resistance in obese children.

METHODS

Forty-seven children with severely obesity aged 7-14 years and 45 age- and gender matched healthy children with normal weight (control group) were enrolled. The levels of height, weight, waistline, hip circumference, fasting blood glucose (FBG), fasting insulin (FINS), triglyceride (TG), total cholesterol (TC), free fatty acid (FFA), interleukin-6 (IL-6) and miR-122 in the two groups were measured. Body mass index (BMI), waist-hip ratio (WHR) and insulin resistance index (HOMA-IR) were calculated.

RESULTS

Compared with the control group, the height, weight, BMI, WHR, FINS, HOMA-IR, TG, FFA, IL-6, and miR-122 levels in the obese group were significantly increased (P<0.05). MiR-122 levels in the obese group were positively correlated with FINS, HOMA-IR and IL-6 levels (r=0.408, 0.442, and 0.464 respectively, P<0.05). The changes of miR-122 have a linear regression relationship with IL-6 (b'=0.318, P<0.05).

CONCLUSIONS

The elevated serum miR-122 levels may be correlated with insulin resistance in obese children. The mechanism needs to be further studied.

Short-term high-fat diet exacerbates insulin resistance and glycolipid metabolism disorders in young obese men with hyperlipidemia, as determined by metabolomics analysis using ultra-HPLC-quadrupole time-of-flight mass spectrometry

BACKGROUND

The prevalence of obesity is increasing rapidly worldwide, and dietary intake is strongly associated with obesity-related chronic diseases. However, key metabolic perturbations in obese young men with hyperlipidemia after high-fat diet (HFD) intervention are not yet clear, and remain to be determined. The aim of this study was to investigate the effects of a short-term HFD on glycolipid metabolism, insulin resistance (IR), and urinary metabolomic profiling in young obese men with hyperlipidemia.

METHODS

Sixty young men (19-25 years; 30 normal weight, 30 obese with hyperlipidemia) were enrolled in the study. Differences in metabolomic profiling of urine between normal-weight and obese young men before and after 3 days intake of the HFD were investigated using ultra-HPLC-quadrupole time-of-flight mass spectrometry.

RESULTS

After the HFD intervention, total cholesterol (TC), low-density lipoprotein cholesterol, fasting plasma glucose, insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) were significantly increased and high-density lipoprotein cholesterol was significantly decreased in obese men, but only TC was significantly increased in normal-weight subjects. Based on metabolic differences, normal-weight and obese men, and obese men before and after the HFD intervention could be separated into distinct clusters. Seventeen major metabolites were identified that were associated with type 2 diabetes mellitus, glycolipid metabolism and IR; the changes in these metabolites suggest metabolic changes in young obese males after short-term HFD intake.

CONCLUSIONS

The findings of this study may contribute to increased understanding of the early biological adaptations of obesity with hyperlipidemia to HFD for the early prevention and control of diabetes and IR.

Human herpesvirus 8 infection DNA positivity is associated with low insulin secretion: A case-control study in a sub-Saharan African population with diabetes

BACKGROUND

Viruses have been considered potential triggers for the development of diabetes. This study assessed insulin secretion and insulin sensitivity in human herpesvirus 8 (HHV8)-infected and uninfected sub-Saharan African people with diabetes.

METHODS

In all, 173 people with non-autoimmune diabetes were enrolled consecutively: 124 with type 2 diabetes mellitus (T2DM) and 49 with ketosis-prone diabetes (KPD) admitted in hyperglycemic crisis. Those with KPD were further subdivided into those with new-onset ketotic-phase KPD (n = 34) or non-ketotic phase KPD (n = 15). All participants were screened for HHV8-specific antibodies and genomic DNA. Blood samples were collected for analysis of fasting glucose, HbA1c, lipid profile, and C-peptide, with insulin resistance and secretion estimated by homeostasis model assessment.

RESULTS

Among the 173 diabetic participants, 88 (50.9%) were positive for HHV8 antibodies (Ac-HHV8+), including 15 (8.7%) positive for HHV8 DNA (DNA-HHV8+). The seroprevalence of HHV8 was similar between T2DM (55.6%) and KPD (61.2%) subjects. Of those with and without ketotic-phase KPD, 35.3% and 46.7% were Ac-HHV8+, respectively. Body mass index was significantly in lower DNA-HHV8+ than DNA-HHV8- subjects. Low-density lipoprotein and total cholesterol were significantly higher, but C-peptide and homeostatic model assessment of β-cell function (HOMA-β) were significantly lower in DNA-HHV8+ than DNA-HHV8- participants. After excluding DNA-HHV8+ participants, triglyceride concentrations were significantly higher in Ac-HHV8+ (n = 73) than Ac-HHV8- (n = 85) subjects. In contrast, HOMA-β was significantly higher among Ac-HHV8+ than Ac-HHV8- participants.

CONCLUSIONS

In the present study, HHV8 DNA positivity was associated with low insulin secretion in this sub-Saharan African diabetes population.

宫内发育迟缓对新生儿胰岛素敏感性和脂联素水平的影响

OBJECTIVE

To explore the effect of intrauterine growth retardation (IUGR) on insulin sensitivity in neonates and the relationship between insulin sensitivity and plasma adiponectin level.

METHODS

Eighty-two term neonates with IUGR and 90 term neonates born appropriate for gestational age (AGA) were enrolled. Weight, height, head circumference and abdomen circumference of the neonates were measured within 24 hours after birth. Fasting serum glucose (FG), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), plasma insulin and adiponectin were detected in two groups on the 7th day after birth. Homeostasis model assessment for insulin resistance (HOMA-IR) index and insulin sensitivity index (ISI) were calculated.

RESULTS

There were no significant differences in the levels of FG, TG, HDL and LDL between the IUGR and AGA groups (P>0.05). The plasma insulin level in the IUGR group was higher than that in the AGA group, but the plasma adiponectin level was lower than that in the AGA group (P<0.05). HOMA-IR index in the IUGR group was higher than that in the AGA group, but ISI was lower than that in the AGA group (P<0.05). Both Pearson correlation analysis and multiple linear regression analysis showed HOMA-IR index was negatively correlated with plasma adiponectin level and birth weight (P<0.05).

CONCLUSIONS

The neonates with IUGR display a higher plasma insulin level and decreased insulin sensitivity. The decreased plasma adiponectin level may be associated with the decreased insulin sensitivity.

Utility of three novel insulin resistance-related lipid indices for predicting type 2 diabetes mellitus among people with normal fasting glucose in rural China

BACKGROUND

Inexpensive and easily measured indices are needed for the early prediction of type 2 diabetes mellitus (T2DM) in rural areas of China. The aim of this study was to compare triglyceride glucose (TyG), visceral adiposity (VAI), and lipid accumulation product (LAP) with traditional individual measures and their ratios for predicting T2DM.

METHODS

Data for 11 113 people with baseline normal fasting glucose in a rural Chinese cohort were followed for a median of 6.0 years. Cox proportional hazards regression was used to calculate covariate-adjusted hazard ratios (aHRs) and 95% confidence intervals (95% CIs) and receiver operating characteristic analysis was used to compare the ability of traditional measures and TyG, VAI, and LAP at baseline to predict T2DM at follow-up.

RESULTS

Among individual measures, fasting plasma glucose (FPG) and waist circumference (WC) were strongly associated with T2DM. Of all lipid ratios, an elevated triglycerides (TG) to high-density lipoprotein cholesterol (HDL-C) ratio was associated the most with T2DM. Compared with the first quartiles of TyG, VAI, and LAP, their fourth quartiles were associated with T2DM for men (aHR 3.54 [95% CI 2.08-6.03], 2.89 [1.72-4.87], and 5.02 [2.85-8.85], respectively) and women (6.15 [3.48-10.85], 4.40 [2.61-7.42], and 6.49 [3.48-12.12], respectively). For predicting T2DM risk, TyG, VAI, and LAP were mostly superior to the TG:  HDL-C ratio, but did not differ from FPG and WC.

CONCLUSIONS

Prediction of T2DM was not improved by TyG, VAI, and LAP versus FPG or WC alone. Therefore, TyG, VAI, and LAP may not be inexpensive tools for predicting T2DM in rural Chinese people.

Association between plasma trans-fatty acid concentrations and diabetes in a nationally representative sample of US adults

BACKGROUND

A diet high in trans-fatty acids (TFA) induces insulin resistance in rodent models and primates. However, previous epidemiological studies on the association between TFAs, based primarily on self-reported intake from the diet, and diabetes in humans have yielded conflicting results. Herein we examined the associations of objectively measured plasma TFA concentrations with diabetes in a large population-based study among US adults.

METHODS

We included 3801 participants aged ≥20 years from the National Health and Nutrition Examination Survey 1999-2000 and 2009-10. Four major TFAs, namely palmitelaidic acid (C16:1 n-7t), elaidic acid (C18:1 n-9t), vaccenic acid (C18:1 n-7t), and linolelaidic acid (C18:2 n-6t, 9t), were measured in fasting plasma using gas chromatography-mass spectrometry. Diabetes was defined by self-reported physician diagnosis, plasma fasting glucose ≥126 mg/dL, or HbA1c ≥6.5%.

RESULTS

After adjustment for other major risk factors, the odds ratios (95% confidence intervals) of diabetes comparing the highest with lowest quintile of plasma TFAs was 2.19 (1.27-3.79) for total TFAs (P_trend  = 0.01), 2.34 (1.48-3.72) for elaidic acid (P_trend  = 0.0004), 1.33 (0.82-2.15) for linolelaidic acid (P_trend  = 0.18), 1.58 (0.97-2.58) for palmitelaidic acid (P_trend  = 0.02), and 1.64 (0.95-2.84) for vaccenic acid (P_trend  = 0.08). In addition, total TFAs, elaidic acid, palmitelaidic acid, and vaccenic acid were significantly associated with fasting glucose, fasting insulin, the insulin resistance index, and HbA1c.

CONCLUSIONS

In a nationally representative population, plasma TFAs, in particular elaidic acid, were positively associated with diabetes and biomarkers of glucose metabolism.

Serum fetuin-B is positively associated with intrahepatic triglyceride content and increases the risk of insulin resistance in obese Chinese adults: A cross-sectional study

BACKGROUND

Fetuin-B impairs insulin action in myotubes and hepatocytes and causes glucose intolerance in mice. This study explored the correlation between serum fetuin-B and intrahepatic triglyceride (IHTG) content, and the association between fetuin-B and the risk of insulin resistance in the general adult population.

METHODS

A cross-sectional study of 1318 obese adults who underwent serum fetuin-B testing and hepatic ultrasonography was conducted in Xiamen, China. The IHTG content was determined in 428 subjects by magnetic resonance spectroscopy.

RESULTS

Non-alcoholic fatty liver disease prevalence was significantly higher in those with the highest serum fetuin-B concentrations and the highest IHTC content (Tertile 3) than in subjects in Tertiles 1 and 2 (62.6% vs 60.7% and 54.3%, respectively [P = 0.032], and 15.3% vs 12.8% and 12.7%, respectively [P = 0.049]). There was a significant association between increasing serum fetuin-B tertiles and both increasing fasting insulin concentrations (mean [± SD] 11.9 ± 6.8, 12.7 ± 7.6, and 13.3 ± 6.4 mIU/L in Tertiles 1, 2 and 3, respectively; P = 0.006) and prevalence of insulin resistance (54.4%, 58.9%, and 64.5% in Tertiles 1, 2 and 3, respectively; P = 0.010). In linear regression analysis, IHTG content was independently and positively correlated with serum fetuin-B (regression coefficient 0.015; P = 0.045). With adjustment for potential confounders, serum fetuin-B was independently associated with increased risk of insulin resistance, with an adjusted odds ratio per standard deviation increase in fetuin-B of 1.14 (95% confidence interval 1.01-1.30; P = 0.031).

CONCLUSIONS

The results demonstrate the role of fetuin-B linking liver fat accumulation to insulin resistance in humans.

Optimism, pessimism, cynical hostility, and biomarkers of metabolic function in the Women's Health Initiative

BACKGROUND

Psychological attitudes reflecting expectations about the future (optimism, pessimism) and people (cynical hostility) independently predict incident cardiovascular disease and possibly diabetes, but underlying biologic pathways are incompletely understood. Herein we examined the cross-sectional relationship between optimism, pessimism, and cynicism and biomarkers of metabolic function in the Women's Health Initiative.

METHODS

Among 3443 postmenopausal women, biomarkers of metabolic function (fasting insulin [FINS] and glucose) were measured at baseline and used to calculate insulin resistance (homeostasis model assessment of insulin resistance [HOMA-IR]) and pancreatic β-cell activity (homeostasis model assessment of β-cell function [HOMA-B]). Psychological attitudes were assessed by the Life Orientation Test, Revised (full scale, and optimism and pessimism subscales) and the Cook-Medley cynicism subscale. Multivariable linear regression modeled the association of psychological attitudes with biomarker levels, adjusting for sociodemographics, health conditions, and health behaviors. Because obesity promotes insulin resistance and obese individuals tend to report higher levels of pessimism and cynical hostility, an interaction with body mass index (BMI) was explored.

RESULTS

In fully adjusted models, only pessimism remained independently associated with higher FINS and insulin resistance (HOMA-IR). Scoring 1 point higher on the pessimism subscale was associated with a 1.2% higher FINS, whereas scoring 1 SD higher was associated with a 2.7% higher FINS (P = 0.03); results were similar for HOMA-IR. An interaction term with BMI was not significant.

CONCLUSIONS

In multivariable models, higher dispositional pessimism was associated with worse metabolic function; these findings were not modified by obesity status. Results extend prior work by linking pessimism to an objective biomarker of insulin resistance in elderly women.

Zinc supplementation in prediabetes: A randomized double-blind placebo-controlled clinical trial

BACKGROUND

This study evaluated the effects of zinc supplementation on glycemic control, other cardiometabolic and anthropometric parameters, and disease progression in prediabetes.

METHODS

A randomized double-blind placebo-controlled Phase 2 clinical trial was conducted over a 12-month period in 200 subjects (43% male; mean [± SD] age 51.8 ± 7.3 years), randomly assigned (1:  1) to the treatment or control group. The treatment group received zinc (20 mg daily). Subjects were evaluated at baseline and at 1, 3, 6, and 12 months. The primary outcome was the change in glycemic control from baseline. Multiple regression analyses were performed, with change in outcome variables after intervention from baseline used as continuous dependent variables.

RESULTS

In both groups, mean serum zinc concentrations prior to the trial were below normal (15.29-21.41 μmol/L). During the 12-month follow-up, a significantly higher percentage of participants developed type 2 diabetes in the control compared with zinc-treated group (25.0% vs 11.0% respectively; P = 0.016). Fasting plasma glucose (FPG), 2-h glucose levels in the oral glucose tolerance test (OGTT), homeostasis model assessment of insulin resistance (HOMA-IR), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) were significantly lower in the treated group, with significant improvement in β-cell function. In all four regression models, the best predictor of the dependent variables (i.e. change in FPG, 2-h glucose in the OGTT, HOMA-IR, and homeostatic model assessment of β-cell function) was zinc treatment.

CONCLUSIONS

Zinc supplementation reduced blood glucose and insulin resistance while improving β-cell function. Furthermore, supplementation reduced disease progression to diabetes and had beneficial effects on TC and LDL-C.

High dietary intake of branched-chain amino acids is associated with an increased risk of insulin resistance in adults

BACKGROUND

The aim of this study was to investigate the association between branched-chain amino acid (BCAA) intake and markers of insulin metabolism in adults.

METHODS

This cohort study was conducted within the framework of the Tehran Lipid and Glucose Study on 1205 subjects, aged ≥20 years, who were followed-up for a mean of 2.3 years. Dietary intake of BCAAs, including valine, leucine, and isoleucine, was determined using a valid and reliable food frequency questionnaire. Hyperinsulinemia, β-cell dysfunction, insulin resistance (IR), and insulin insensitivity were determined according to optimal cut-off values. Logistic regression was to estimate the occurrence of IR across tertiles of BCAA intake.

RESULTS

The mean (± SD) age and BCAA intake of participants (43% male) at baseline were 42.7 ± 13.1 years and 13.8 ± 5.1 g/day, respectively. The incidence of hyperinsulinemia, β-cell dysfunction, insulin insensitivity, and IR was 19.5%, 24.0%, 28.0%, and 12.5%, respectively. After adjustment for confounding variables, subjects in the highest tertile for total BCAAs (odds ratio [OR] 1.67; 95% confidence interval [CI] 1.03-2.71), leucine (OR 1.75; 95% CI 1.09-2.82), and valine (OR 1.61; 95% CI 1.01-2.60) intake had a greater risk of incident IR than subjects in the lowest tertile. A higher intake of isoleucine was not associated with risk of incident IR. There was no association of total BCAAs, leucine, isoleucine, and valine intake with the risk of hyperinsulinemia, insulin insensitivity, or β-cell dysfunction.

CONCLUSION

The findings of this study support the hypothesis that higher intakes of BCAAs may have adverse effects on the development of IR.

Evaluation of the Chinese herbal medicine Jinlida in type 2 diabetes patients based on stratification: Results of subgroup analysis from a 12-week trial

BACKGROUND

The Chinese herbal medicine Jinlida can significantly enhance the hypoglycemic action of metformin. However, the population showing the best responses to Jinlida has not been clarified. The aim of the present study was to compare the efficacy of Jinlida in type 2 diabetes mellitus (T2DM) after stratification.

METHODS

Data were analyzed from a 12-week randomized placebo-controlled double-blind multicenter study with 192 T2DM patients (186 completed the study). The efficacy evaluation included HbA1c, fasting plasma glucose (FPG), and 2-h postprandial glucose (2hPG) levels stratified by baseline HbA1c, sex, age, body mass index (BMI), and duration of T2DM diagnosis. Homeostasis model assessment of insulin resistance (HOMA-IR) and homeostatic model assessment of β-cell function (HOMA-β) were also evaluated stratified by baseline insulin levels.

RESULTS

In the Jinlida group, HbA1c was significantly reduced (P < 0.05). Greater reductions were observed in patients with baseline HbA1c >8.5%, in males and in those aged >60 years, with a BMI ≤24 kg/m² , or with a duration of T2DM diagnosis >5 years (P < 0.05). Compared with baseline, Jinlida significantly alleviated insulin resistance (P < 0.05) in patients with baseline insulin levels >20 mU/L. Jinlida also significantly improved β-cell function in patients with baseline insulin levels ≤20 mU/L (P < 0.05).

CONCLUSIONS

Jinlida significantly improved glycemic control, with greater improvements in patients with poor glycemic control and male, elderly, of normal weight, or with a long disease course. Furthermore, Jinlida alleviated insulin resistance with hyperinsulinemia and promoted insulin secretion with hypoinsulinemia. These results need to be further confirmed in clinical trials.

[Correlation between ectopic fat accumulation and insulin sensitivity in obese individuals with different glucose tolerance levels]

OBJECTIVE

To investigate the correlation between liver and skeletal muscle fat contents and insulin resistance in obese individuals with different levels of glucose tolerance.

METHODS

RESULTS: Ten non-obese individuals with normal glucose tolerance (NGT), 9 obese individuals with NGT, and 7 obese individuals with impaired glucose tolerance (IGT) were enrolled in this study. All the participants were examined for insulin sensitivity by hyperinsulinemic-euglycemic clamp and for liver and skeletal muscle fat accumulation quantified by proton magnetic resonance spectroscopy (1H MRS). The data were collected from the subjects including somatometric measurements, fasting plasma glucose, 2-h plasma glucose (2hPG), fasting insulin, and blood biochemistry. Linear correlation analysis and multiple linear stepwise regression analysis were used to analyze the relationship between ectopic fat accumulation and insulin resistance.

RESULTS

The glucose infusion rates (GIR, presented as the M value) differed significantly among IGT-obese (3.95∓1.66 mg·kg^-1·min^-1), NGT-obese (6.14∓1.90 mg·kg^-1·min^-1) and NGT-non-obese (8.78∓2.46 mg·kg^-1·min^-1) groups (P<0.05). The 3 groups also showed significant differences in liver fat contents [(15.23∓3.09)%, (6.25∓0.38)%, and (1.89∓0.90)%, respectively, P<0.05] and intramyocellular lipids in the tibialis anterior (2.69∓0.95, 2.61∓1.45, and 1.54∓0.66 mmol/kg, respectively, P<0.05). Linear analysis revealed that liver fat content, but not skeletal muscle fat content, was significantly correlated with the M value. Multiple linear stepwise regression analysis using M value as the dependent variable (Y) revealed that liver fat content (X) was an independent factor inversely correlated with the M value (regression equation: Y=-30.562X+9.007, R²=0.717, P<0.01).

CONCLUSIONS

Liver fat accumulation, but not skeletal muscle fat accumulation, is correlated with insulin resistance and impaired glucose metabolism.

[Association of waist-to-hip ratio with insulin resistance in non-diabetic normal-weight individuals: a cross-sectional study]

OBJECTIVE

To explore the relationship between waist-to-hip ratio (WHR) and insulin resistance(IR) in non-diabetic normal-weight individuals and investigate how this association differs between male and femalesubjects.

METHODS

From June to October, 2012, we performed a cross-sectional survey among 2142 community-based non-diabetic Chinese participants, who were divided into 4 groups according to the gender-specific quartiles of WHR. Homeostatic model assessment of insulin resistance (HOMA-IR), calculated as the product of fasting plasma glucose (mmol/L) and fasting insulin (mU/L) divided by 22.5, was used as the indicator of insulin resistance. Logistic regression models were used to explore the association of WHR with IR in these subjects.

RESULTS

In the unadjusted model, WHR was significantly associated with IR in women (OR=6.60, 95%CI: 2.86-15.26, P<0.001); the association was still significant (OR=3.28, 95%CI: 1.34-8.04, P=0.009) after adjustment for the potential confounders including the history of hypertension, coronary heartdisease, current smoker, physical inactivity, and body mass index.

CONCLUSION

WHR is independently associated with IR in non-diabetic Chinese women with normal body weight.

[Association of waist-to-hip ratio with insulin resistance in non-diabetic normal-weight individuals: a cross-sectional study]

OBJECTIVE

To explore the relationship between waist-to-hip ratio (WHR) and insulin resistance(IR) in non-diabetic normal-weight individuals and investigate how this association differs between male and femalesubjects.

METHODS

From June to October, 2012, we performed a cross-sectional survey among 2142 community-based non-diabetic Chinese participants, who were divided into 4 groups according to the gender-specific quartiles of WHR. Homeostatic model assessment of insulin resistance (HOMA-IR), calculated as the product of fasting plasma glucose (mmol/L) and fasting insulin (mU/L) divided by 22.5, was used as the indicator of insulin resistance. Logistic regression models were used to explore the association of WHR with IR in these subjects.

RESULTS

In the unadjusted model, WHR was significantly associated with IR in women (OR=6.60, 95%CI: 2.86-15.26, P<0.001); the association was still significant (OR=3.28, 95%CI: 1.34-8.04, P=0.009) after adjustment for the potential confounders including the history of hypertension, coronary heartdisease, current smoker, physical inactivity, and body mass index.

CONCLUSION

WHR is independently associated with IR in non-diabetic Chinese women with normal body weight.

Effects of weekly supervised exercise or physical activity counseling on fasting blood glucose in women diagnosed with gestational diabetes mellitus: A systematic review and meta-analysis of randomized trials

BACKGROUND

Exercise is an important part of gestational diabetes mellitus (GDM) lifestyle management. However, no meta-analysis has analyzed the effects of exercise programs on fasting blood glucose (FBG) in women with GDM. A systematic review with meta-analysis was performed to evaluate the effects of weekly supervised exercise (EXE) or physical activity counseling (PA) in women with GDM compared with usual prenatal care (UPN) on glycemic control.

METHODS

Eligible trials were identified from Medline, EMBASE, Web of Science, Scopus and SportDiscus up to December 2016. Data were retrieved from randomized controlled trials comparing UPN with UPN plus weekly supervised (at least once a week) prenatal exercise or PA counseling for which FBG values before and after intervention were available. Random-effects meta-analysis was performed for mean difference in FBG after exercise intervention.

RESULTS

The search yielded 781 publications, of which 82 were assessed for eligibility and eight were included in the meta-analysis. The overall effect on absolute FBG concentrations was not significant (P = 0.11) compared with UPN. However, PA versus UPN showed a significant reduction in absolute FBG concentrations (weighted mean difference -3.88 mg/dL; 95% confidence interval -7.33, -0.42 mg/dL; I ² 48%; P _{heterogeneity}  < 0.15).

CONCLUSIONS

Physical activity counseling in women with GDM showed a significant effect compared with UPN on FBG concentrations, possibly due to a longer follow-up time compared with the EXE groups. This result highlights the importance of an early intervention that lasts to delivery for best practice of GDM management.

Docosapentaenoic acid and docosahexaenoic acid are positively associated with insulin sensitivity in rats fed high-fat and high-fructose diets

BACKGROUND

The aim of the present study was to compare insulin resistance and metabolic changes using a global lipidomic approach.

METHODS

Rats were fed a high-fat diet (HFD) or a high-fructose diet (HFrD) for 12 weeks to induce insulin resistance (IR) syndrome. After 12 weeks feeding, physiological and biochemical parameters were examined. Insulin sensitivity and plasma metabolites were evaluated using a euglycemic-hyperinsulinemic clamp and mass spectrometry, respectively. Pearson's correlation coefficient was used to investigate the strength of correlations.

RESULTS

Rats on both diets developed IR syndrome, characterized by hypertension, hyperlipidemia, hyperinsulinemia, impaired fasting glucose, and IR. Compared with HFrD-fed rats, non-esterified fatty acids were lower and body weight and plasma insulin levels were markedly higher in HFD-fed rats. Adiposity and plasma leptin levels were increased in both groups. However, the size of adipocytes was greater in HFD- than HFrD-fed rats. Notably, the lipidomic heat map revealed metabolites exhibiting greater differences in HFD- and HFrD-fed rats compared with controls. Plasma adrenic acid levels were higher in HFD- than HFrD-fed rats. Nevertheless, linoleic and arachidonic acid levels decreased in HFrD-fed rats compared with controls. Plasma concentrations of docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) were significantly reduced after feeding of both diets, particularly the HFrD. There was a strong positive correlation between these two fatty acids and the insulin sensitivity index.

CONCLUSIONS

The systemic lipidomic analysis indicated that a reduction in DHA and DPA was strongly correlated with IR in rats under long-term overnutrition. These results provide a potential therapeutic target for IR and metabolic syndrome.

[Effect of metformin on insulin resistance during catch-up growth in mice with fetal growth restriction]

OBJECTIVE

To study the efficacy of metformin intervention on insulin resistance during catch-up growth in mice with fetal growth restriction (FGR).

METHODS

Mouse models of FGR were established by low protein diet feeding of the pregnant mice. Both the newborn female mice with FGR and normal control (NC) mice were randomized for feeding with a standard diet (SF) or a high-fat diet (HF) after weaning and treatment with gavage of either metformin or normal saline. The mice were examined for vaginal opening time and the estrous cycle at the age of 8 weeks. At the age of 12 weeks, 6 mice in anestrus from each group were fasted for 12 h for measurement of body weight, height, poundera index (PI), fasting blood glucose (FBG), fasting insulin (Fins), follicle stimulating hormone (FSH) and anti-Mullerian hormone (AMH), and the HOMA-IR was calculated. The reproductive capacity of female mice was assessed by mixing them with male mice at the ratio of 2:1. The 3 × 2 factorial analysis was conducted to determine the interactions between FGR, high-fat feeding and metformin.

RESULTS

Factorial analysis showed that FGR and high-fat feeding had significant effects on the PI index, Fins, HOMA-IR, vaginal opening time, and AMH (P<0.05). Metformin significantly affected the factors related to high-fat feeding including weight, PI, FPG, Fins, HOMA-IR and estrous cycle (P<0.05) and the factors related to FGR with the exception of height and FSH (P<0.05). FGR significantly affected the factors tested except for body weight (P<0.05); high-fat feeding affected all the factors but the FSH (P<0.05); metformin affected all the factors but the height and FSH (P<0.05). In the female mice treated with saline, the pregnancy rates differed significantly between FGR mice with high-fat feeding and control mice with standard feeding, and between FGR mice with standard feeding and high-fat feeding (P<0.05).

CONCLUSION

FGR mice can present with delayed puberty with rare ovulation and adulthood insulin resistance, and high-fat feeding after birth can promote the catch-up growth of FGR mice. Metformin intervention is effective for improving insulin resistance and reproductive-endocrine disorders in FGR mice during catch-up growth.

Effect of pioglitazone on metabolic features in endotoxemia model in obese diabetic db/db mice

BACKGROUND

Infectious diseases are more frequent in diabetic patients, leading to increased morbidity and mortality. Endotoxemia affects glucose metabolism and lipolytic capacity. The aims of the present study were to determine whether endotoxemia exacerbates metabolic features (adipose inflammation, adipogenesis, and insulin resistance [IR]) in an animal model of diabetes (i.e. db/db mice) after acute infection and the effects of pioglitazone.

METHODS

Female db/db mice treated with pioglitazone (3 and 30 mg/kg, p.o.) for 14 days were challenged with lipopolysaccharide (LPS; 200 μg/kg), followed by an oral glucose tolerance test (OGTT). Quantitative real-time polymerase chain reaction (PCR) was used to evaluate the expression of genes in white adipose tissue (WAT) involved in: (i) adipogenesis (lipoprotein lipase [Lpl], fatty acid binding protein-4 [Ap2] and adiponectin [Adipoq]); (ii) insulin signaling (peroxisome proliferator-activated receptor gamma [Pparg], suppressor of cytokine signaling 3 [Socs3], solute carrier family 2 [facilitated glucose transporter], member 4 [Slc2a4]); and (iii) inflammation (tumor necrosis factor [Tnf], interleukin-6 [Il6], monocyte chemoattractant protein-1 [Ccl2], cyclo-oxygenase-2 [prostaglandin-endoperoxide synthase 2; Ptgs2]).

RESULTS

Experimental endotoxemia downregulated mRNA expression of Pparg, Slc2a4, Adipoq, Lpl, and Ap2, which coincided with upregulation of Il6, Tnf, Ccl2, Ptgs2, and Socs3 expression. Pioglitazone dose-dependently decreased Tnf, Il6, Ccl2, Ptgs2, and Socs3 expression in WAT, in association with upregulation of Lpl, Ap2, Slc2a4, and Adipoq expression, indicating improvement in endotoxin-induced IR.

CONCLUSIONS

The findings suggest that LPS challenge exacerbates IR in db/db mice by altering the expression of genes in WAT involved in adipogenesis and inflammation, which is effectively controlled by pioglitazone treatment.

Resveratrol inhibits inflammation and ameliorates insulin resistant endothelial dysfunction via regulation of AMP-activated protein kinase and sirtuin 1 activities

BACKGROUND

Resveratrol is a phytoalexin with beneficial effects on human health. The aim of the present study was to investigate the effects of resveratrol on endothelial dysfunction involved in insulin signaling and inflammation.

METHODS

Endothelial cells were stimulated with palmitate (PA) to induce insulin resistance characterized by a loss of insulin-mediated nitric oxide (NO) production. Diabetes was induced in rats by fructose feeding. The effects of resveratrol and the mechanisms involved were investigated using an aortic relaxation assay and Western blot analysis.

RESULTS

In endothelial cells, 0.1-10 μmol/L resveratrol suppressed IκB kinase β (IKKβ)/nuclear factor-κB phosphorylation, as well as tumor necrosis factor-α and interleukin-6 production, and restored the insulin receptor substrate-1 (Irs-1)/Akt/endothelial NO synthase signaling pathway. Furthermore, resveratrol effectively inhibited the mitogenic actions of insulin by decreasing the secretion of endothelin-1 and plasminogen activator inhibitor-1. It also positively regulated AMP-activated kinase (AMPK) and sirtuin 1 (SIRT1) activation, which contributed to the inhibition of inflammation implicated in endothelial insulin resistance. Stimulation with PA and long term-fructose feeding impaired insulin-mediated vessel dilation in rat aorta, whereas pretreatment of aortic rings with resveratrol (0.1-10 μmol/L) or treatment of rats with 5 or 20 mg/kg resveratrol counteracted these changes.

CONCLUSION

The results indicate that resveratrol inhibits inflammation and facilitates insulin phosphatidylinositol 3-kinase signaling by beneficial modulation of IRS-1 function partly via regulation of AMPK and SIRT1 activity in the endothelium.

Insulin resistance is associated with all chronic complications in type 1 diabetes

BACKGROUND

Insulin resistance (IR) is present in type 1 diabetes mellitus (T1DM) and is suggested to be related to chronic diabetic complications. The primary aim of our study was to assess IR in T1DM patients with and without chronic complications. A secondary aim was to evaluate the possible association between IR and chronic diabetic complications.

METHODS

This cross-sectional study enrolled 272 patients with T1DM. Insulin resistance was quantified using the estimated glucose disposal rate (eGDR). Associations between eGDR and each diabetes complication were first evaluated using binary logistic regression, then multiparametric logistic regression with stepwise selection of covariates. The discriminative value of eGDR was assessed by receiver operating characteristic (ROC) curve analysis.

RESULTS

Estimated GDR was lower in patients with chronic diabetic complications (6.1 vs. 6.9 mg/kg per min [P = 0.02] for retinopathy; 6.3 vs. 7.3 mg/kg per min [P < 0.01] for nephropathy; 6.5 vs. 7.6 mg/kg per min [P < 0.01] for neuropathy; and 5.2 vs. 7.5 mg/kg per min [P < 0.01] for cardiovascular complications). In univariate analysis eGDR was associated all diabetic complications. These associations remained significant after adjustment for different variables in the final regression models. In addition, eGDR was a good discriminator for each diabetic complication, with an area under the curve between 0.609 and 0.759.

CONCLUSIONS

Patients with chronic diabetic complications are more insulin resistant than those without complications. Moreover, IR was independently associated with the presence of each chronic diabetic complication, and seems to be a good discriminator for them all.