Optimal Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) Cut-Offs: A Cross-Sectional Study in the Czech Population

Comparisons of various insulin resistance indices for new-onset metabolic syndrome before midlife: The CHIEF cohort study, 2014-2020

BACKGROUND

Some non-insulin-based insulin resistance (IR) indices have been found to be associated with metabolic syndrome (MetS); however, few cohort studies have compared the capacities of these indices for predicting incident MetS in young adults.

AIM

To investigate the associations of various non-insulin-based IR (NI-IR) indices with new-onset MetS in young military personnel.

METHODS

A total of 2890 armed forces personnel in Taiwan who were aged 18-39 years and did not have MetS at baseline were followed to monitor the incidence of new-onset MetS from 2014 to the end of 2020. Six NI-IR indices, including the metabolic score for IR (METS-IR), triglyceride (TG)-to-high-density lipoprotein cholesterol (HDL-C) ratio, TG glucose (TyG) index, Zhejiang University (ZJU) index, total cholesterol (TC)-to-HDL-C ratio, and alanine transaminase (ALT)-to-aspartate transaminase (AST) ratio, were defined according to specific criteria. Incident MetS was identified on the basis of each annual health examination using the International Diabetes Federation criteria. Multiple Cox regression analyses were conducted, adjusting for age, sex, waist circumference, smoking status, alcohol consumption status, and physical activity, to assess the associations of the NI-IR indices with incident MetS. The area under the receiver operating characteristic curve (AUROC) was used to compare the capacities of these NI-IR indices for predicting new-onset MetS.

RESULTS

During a median follow-up of 5.8 years, there were 673 patients with new-onset MetS (23%). All six of the NI-IR indices were significantly and positively associated with incident MetS. In the entire cohort, the greatest AUROC was found for the METS-IR [0.782; 95% confidence interval (CI): 0.762-0.801; all P values compared to the other NI-IR indices < 0.05], followed by the TG/HDL-C ratio (0.752; 95%CI: 0.731-0.772), ZJU index (0.743; 95%CI: 0.722-0.764), TyG index (0.734; 95%CI: 0.713-0.756), TC/HDL-C ratio (0.731; 95%CI: 0.709-0.752), and then the ALT/AST ratio (0.734; 95%CI: 0.713-0.756).

CONCLUSION

This study suggests that almost all the NI-IR indices are associated with the development of MetS in military young adults. The METS-IR is the strongest predictor of new-onset MetS before midlife.

Nitrate reduction by salivary bacteria, glucose metabolism, and lifestyle

Background

Nitrate reductases (NR) expressed in oral bacteria reduce nitrate to nitrite. Depending on the environmental conditions and types of bacteria present nitrite can be further reduced to ammonium via Dissimilatory Nitrate Reduction to Ammonium (DNRA), or alternatively to nitric oxide (NO), which impacts cardiometabolic health.

Objective

To evaluate the associations between nitrate reduction by salivary bacteria, clinical markers of glucose metabolism, and lifestyle factors that can modulate the oral environment, potentially impacting DNRA and NR expression.

Methods

A cross-sectional study was conducted using a convenience sample of 144 participants from the San Juan Overweight Adult Longitudinal Study (SOALS), which includes data on glucose metabolism and lifestyle. DNRA and NR activities were measured in saliva under aerobic or CO2-enriched conditions.

Results

DNRA activity was inversely associated with insulin resistance (HOMA-IR) [aerobic3rd vs.1st tertile: β=-0.48 (-0.81, -0.15); CO2-enriched3rd vs.1st tertile β=-0.42 (-0.68, -0.17)], fasting blood glucose [aerobic3rd vs.1st tertile β=-0.144 (-0.268, -0.019); CO2-enriched3rd vs.1st tertile: β=-0.070 (-0.130, -0.011)], and 2-h glucose [CO2-enriched3rd vs.1st tertileβ=-0.21 (-0.37, -0.04)]. Current smokers had lower DNRA activity than non-smokers under aerobic conditions [β=-1.55 (-2.96, -0.14)], but higher under CO2-enriched conditions [β = 0.93 (0.15, 1.71)]. Toothbrushing frequency (twice/day vs. once/day) was positively associated with DNRA activity under CO2-enriched conditions [β = 4.11 (1.90, 6.32)] and with aerobic NR activity [β = 1.20, (0.14, 2.27)]. Physical activity was inversely associated with aerobic NR [β=-0.01, (-0.022, -0.003)]. Under CO2-enriched conditions NR was inversely associated with the BMI (β=-0.11, p = 0.007). Aerobic NR was higher when sucrose was added to the assays (NADP vs. sucrose β=-0.74, p = 0.02) and positively associated with salivary nitrate levels (β = 0.002, p = 0.002).

Conclusions

Nitrate reduction by salivary bacteria is inversely associated with insulin resistance and can be modulated by lifestyle factors. This knowledge could lead to the development of novel, non-invasive approaches for monitoring and preventing diabetes progression.

The impact of insulin resistance on thyroid function and the prevalence of thyroid follicular nodular disease in pregnant women

Introduction

Insulin resistance (IR) is a phenomenon commonly observed in pregnancy. Increased insulin concentrations might impact thyroid function and structure during gestation.

Objectives

This study investigates the bidirectional relationship between IR indices and thyroid function and morphology in pregnant women.

Methods

In 1,069 gravid participants of the Polish National Programme for Elimination of Iodine Deficiency (2007-2017), blood samples were analyzed for thyroid-stimulating hormone (TSH), FT3, FT4, aTPO, fasting glucose and insulin concentrations, and the thyroid structure was assessed with ultrasound (in 1,065 subjects). Based on calculated homeostatic model assessment of insulin resistance (HOMA-IR) values, participants were stratified into two subgroups: HOMA-nl (HOMA-IR <2.5) and HOMA-h (HOMA-IR ≥2.5), comprising 894 and 175 women, respectively.

Results

Significant difference in mean TSH (1.77 ± 1.17 vs 1.96 ± 1.04; P = 0.008) and mean FT4 (12.65 ± 2.3 vs 11.47 ± 1.9; P = 0.001) concentrations between HOMA-nl and HOMA-h groups was found. The subgroups did not differ in thyroid nodularity or multinodular goiter prevalence. HOMA-IR positively correlated with TSH concentrations, BMI and thyroid volume. Serum FT3 and FT4 concentrations showed negative correlations with HOMA-IR.

Conclusions

IR seems to affect the thyroid function of gravid women by diminishing the ability to respond to increased thyroid hormone demand. Thyroid volume increase during pregnancy may be influenced by IR; however, its short-term effect on thyroid nodularity appears to be negligible.

Sleep duration as a mediator in the association between dietary intake of live microbes and insulin resistance: a cross-sectional study

BACKGROUND

Insulin resistance and associated metabolic health symptoms remain a primary global health concern. In addition to healthy dietary and nutritional programs, sleep duration is closely related to and has been linked to healthy metabolism. This study aimed to determine the link between insulin resistance and sleep duration and the dietary intake of live microbes.

METHODS

Data were collected from 15,927 participants in the National Health and Nutrition Examination Survey database from 2005 to 2018; this sample is equivalent to 209,316,590 individuals in the United States. The participants were categorized according to their consumption of foods containing live microbes: low, medium, high, and medium-high. The relationship between diets containing live microbes and the triglyceride-glucose index was analysed using a weighted multivariate linear regression model with a multistage sampling approach. The individuals were deemed to have insulin resistance if their homeostatic model assessment score for insulin resistance was ≥ 2. The relationship between diets containing live microbes and insulin resistance status was assessed using weighted multivariate logistic regression analyses. The mediating role of sleep duration on the relationship between diets containing live microbes and the triglyceride-glucose index was also examined.

RESULTS

After accounting for potential confounders, diets containing live microbes at medium and medium-high levels were significantly associated with a reduced triglyceride-glucose index. The medium and medium-high levels of live microbial intake were also associated with a lower risk of insulin resistance. Within the 6-9 hours' sleep duration range, the indirect effect of medium and medium-high levels of live microbes on the triglyceride-glucose index was observed, accounting for 2.95% and 6.08% of the overall change, respectively.

CONCLUSIONS

This study suggests an association between a diet rich in medium and medium-high viable microbes, lower triglyceride-glucose index values, and a reduced risk of developing insulin resistance. Additionally, a sleep duration of 6-9 h may mediate this association.

Changes in glucose-related parameters according to LDL-cholesterol concentration ranges in non-diabetic patients

The study focused on the changes in C-peptide, glycemia, insulin concentration, and insulin resistance according to LDL-cholesterol concentration ranges. The metabolic profile of individuals in the Czech Republic (n = 1840) was classified by quartiles of LDL-cholesterol into four groups with the following ranges: 0.46-2.45 (n = 445), 2.46-3.00 (n = 474), 3.01-3.59 (n = 459), and 3.60-7.18 mmol/l (n = 462). The level of glucose, C-peptide, insulin, and area of parameters during OGTT and HOMA IR were compared with a relevant LDL-cholesterol range. The evaluation involved correlations between LDL-cholesterol and the above parameters, F-test and t-test. Generally, mean values of glucose homeostasis-related parameters were higher with increasing LDL-cholesterol levels, except for mean HOMA IR values which rapidly increased (2.7-3.4) between LDL-cholesterol ranges of 3.00-3.59 and 3.60-7.18 mmol/l. Glucose, C-peptide, insulin concentrations, and the area of parameters reached greater changes especially after glucose load during OGTT (p ≤ 0.001). Considerable changes were already observed for the above parameters between groups with LDL-cholesterol ranges of 2.46-3.00 and 3.01-3.59 mmol/l. HOMA IR increased with higher LDL-cholesterol concentrations, but the differences in mean values were not statistically significant. Most important differences appeared in glucose metabolism at LDL-cholesterol concentrations of 3.60-7.18 mmol/l in comparison to LDL-cholesterol lower ranges. In particular, the areas of C-peptide, glucose, and insulin ranges showed statistically significant differences between all groups with growing LDL-cholesterol ranges. The variances of HOMA IR statistically differed between groups created according to LDL-cholesterol concentrations ranges.

Visceral and Dysfunctional Adiposity Indices as Predictors of Insulin Resistance and Metabolic Syndrome in Women with Polycystic Ovary Syndrome: A Cross-Sectional Study

Background and Objectives: Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women of reproductive age. Women with PCOS often have metabolic disorders such as insulin resistance (IR), type 2 diabetes (T2DM), obesity, and metabolic syndrome (MetS). The assessment of visceral adiposity and dysfunctional adipose tissue is crucial for understanding the metabolic risks associated with PCOS. The visceral adiposity index (VAI) and the dysfunctional adiposity index (DAI) are two novel metabolic indices that more specifically assess adipose tissue dysfunction and visceral fat accumulation. This study aimed to evaluate the clinical utility of VAI and DAI as predictive markers for metabolic complications such as insulin resistance (IR) and metabolic syndrome (MetS) in women with PCOS. Materials and Methods: This cross-sectional study included 92 women diagnosed with PCOS based on the 2023 revised Rotterdam criteria, as well as 68 healthy controls. Anthropometric and biochemical parameters, including fasting glucose, insulin, lipid profile, and hormonal markers, were recorded. VAI and DAI were calculated using established formulas derived from previous validated studies. Results: The mean VAI in PCOS patients was 4.26 ± 3.23, compared to 2.61 ± 1.92 in controls (p = 0.003). The mean DAI in PCOS patients was 3.00 ± 1.86, while in controls it was 1.86 ± 1.22 (p = 0.003). Both VAI (Area Under the Curve [AUC] = 0.639) and DAI (AUC = 0.635) did not demonstrate statistically significant diagnostic performance for PCOS itself, but they were strongly associated with metabolic disturbances within the PCOS group. VAI and DAI values were significantly elevated in PCOS patients with IR (p < 0.001) and MetS (p < 0.001). For MetS in PCOS patients, VAI demonstrated the highest predictive ability, with an AUC of 0.87 and a cutoff of 4.73 (sensitivity 62%, specificity 92%), while DAI had an AUC of 0.86 with a cutoff of 2.44 (sensitivity 74%, specificity 80%). Regarding IR in PCOS patients, VAI had an AUC of 0.75 with a cutoff of 2.56 (sensitivity 82%, specificity 56%), while DAI had an AUC of 0.74 with a cutoff of 1.59, showing a sensitivity of 82% and a specificity of 55%. Conclusions: Although VAI and DAI are not suitable for diagnosing PCOS, they provide valuable insights into the metabolic risks associated with the condition. VAI and DAI can serve as promising biomarkers for identifying IR and MetS risk in women with PCOS. Their integration into clinical practice may facilitate the early detection of cardiometabolic complications, offering a more specific metabolic risk assessment compared to traditional anthropometric measures.

Biomarkers of insulin sensitivity/resistance

In recent years, remarkable advancements in elucidating the intricate molecular underpinnings of type 2 diabetes mellitus (T2D) have been achieved. Insulin resistance (IR) has been unequivocally acknowledged as the driving pathogenetic mechanism of T2D, preceding disease onset by several years. Nonetheless, diagnostic tools for ascertaining IR are lacking in current clinical practice, representing a critical unmet need; use of the hyperinsulinemic-euglycemic glucose clamp, widely accepted as the gold standard method for evaluating IR at present, is cumbersome in a clinical setting. Thus, the development of well-validated, reliable, and affordable biomarkers of IR has attracted considerable attention from the research community. The biomarkers under investigation can be divided into two major categories: (1) indices or ratios, comprising parameters obtained from a basic or comprehensive metabolic panel and/or derived from anthropometric measurements, and (2) circulating molecules implicated in pathophysiological processes associated with IR. Furthermore, numerous novel biomarkers, including markers of β-cell dysfunction, radiographic quantification of excess visceral adipose tissue, T2D prediction models, certain microRNAs and metabolomic biomarkers, have also provided promising preliminary results. This narrative review aims to present current evidence pertaining to the most notable and exciting biomarkers of IR that are under rigorous evaluation.

Risk factors for cardiovascular disease in women with preeclampsia and intrauterine growth restriction

Objective

To identify the risk factors for cardiovascular disease in women with pre-eclampsia and intrauterine growth retardation.

Methods

This cross sectional study was conducted in Department of Gynecology and Obstetrics, Liaquat University Hospital, Hyderabad, from April 2022 to October 2022. Patients with history of intrauterine growth retardation or preeclampsia after 20 weeks of gestation, age more than 18 years were included in this study. Patients were assessed for cardiovascular risk factors during pregnancy.

Results

The average age and gestational age were almost equal in preeclampsia and IUGR patients, (p≤0.050). The primparous were higher in preeclampsia than IUGR, n=286 (73.5%) and n=80 (52.3%), respectively, (p=0.000). The average birth weight of IUGR was lower than preeclampsia patients, 925.19±6.35 gram and 1324.76±10.19 gram, respectively, (p=0.000). The average systolic and diastolic blood pressure of IUGR patients was less than preeclampsia patients, (p=0.000). But, the chronic hypertension was higher in preeclampsia patients n=99 (25.4%) as compare to IUGR n=13 (8.5%) patients, (p=0.000). The average cholesterol level in IUGR was 5.52±0.58(mmol/L) versus preeclampsia 5.34±1.01(mmol/L), (p=0.043). The average triglycerides was almost equal in both the groups, (p=0.924). The mean Lp(a) in preeclampsia patients was 177.15±20.15(mg/L) versus 202.94±24.83 (mg/L), (p=0.000).

Conclusion

Findings of this study help conclude that women with known history of IUGR or preeclampsia must be screened for possible cardiovascular risk factors and treated for these risk factors in order to avoid future mortality and morbidity associated with cardiovascular diseases.

A novel simple disposition index (SPINA-DI) from fasting insulin and glucose concentration as a robust measure of carbohydrate homeostasis

AIMS

The widely used dynamic disposition index, derived from oral glucose tolerance testing, is an integrative measure of the homeostatic performance of the insulin-glucose feedback control. Its collection is, however, time consuming and expensive. We, therefore, pursued the question if such a measure can be calculated at baseline/fasting conditions using plasma concentrations of insulin and glucose.

METHODS

A new fasting-based disposition index (structure parameter inference approach-disposition index [SPINA-DI]) was calculated as the product of the reconstructed insulin receptor gain (SPINA-GR) times the secretory capacity of pancreatic beta cells (SPINA-GBeta). The novel index was evaluated in computer simulations and in three independent, multiethnic cohorts. The objectives were distribution in various populations, diagnostic performance, reliability and correlation to established physiological biomarkers of carbohydrate metabolism.

RESULTS

Mathematical and in-silico analysis demonstrated SPINA-DI to mirror the hyperbolic relationship between insulin sensitivity and beta-cell function and to represent an optimum of the homeostatic control. It significantly correlates to the oral glucose tolerance test based disposition index and other important physiological parameters. Furthermore, it revealed higher discriminatory power for the diagnosis of (pre)diabetes and superior retest reliability than other static and dynamic function tests of glucose homeostasis.

CONCLUSIONS

SPINA-DI is a novel simple reliable and inexpensive marker of insulin-glucose homeostasis suitable for screening purposes and a wider clinical application.

The effects of grape seed extract supplementation on cardiovascular risk factors, liver enzymes and hepatic steatosis in patients with non-alcoholic fatty liver disease: a randomised, double-blind, placebo-controlled study

BACKGROUND

Despite the high antioxidant potential of grape seed extract (GSE), very limited studies have investigated its effect on non-alcoholic fatty liver disease (NAFLD). Therefore, this study was conducted with the aim of investigating the effect of GSE on metabolic factors, blood pressure and steatosis severity in patients with NAFLD.

METHODS

In this double-blind randomized clinical trial study, 50 NAFLD patients were divided into two groups of 25 participants who were treated with 520 mg/day of GSE or the placebo group for 2 months. The parameters of glycemic, lipid profile, blood pressure and steatohepatitis were measured before and after the intervention.

RESULTS

The GSE group had an average age of 43.52 ± 8.12 years with 15 women and 10 men, while the placebo group had an average age of 44.88 ± 10.14 years with 11 women and 14 men. After 2 months of intervention with GSE, it was observed that insulin, HOMA-IR, TC, TG, LDL-c, ALT, AST, AST/ALT, SBP, DBP and MAP decreased and QUICKi and HDL-c increased significantly (p-value for all < 0.05). Also, before and after adjustment based on baseline, the average changes indicated that the levels of insulin, HOMA-IR, TC, TG, LDL-c, SBP, DBP, MAP in the GSE group decreased more than in the control group (p for all < 0.05). Furthermore, the changes in HDL-c were significantly higher in the GSE group (p < 0.05). The between-groups analysis showed a significant decrease in the HOMA-β and AST before and after adjustment based on baseline levels (p < 0.05). Moreover, the changes in QUICKi after adjustment based on baseline levels were higher in the GSE group than in the control group. Also, between-groups analysis showed that the severity of hepatic steatosis was reduced in the intervention group compared to the placebo group (P = 0.002).

CONCLUSIONS

It seems that GSE can be considered one of the appropriate strategies for controlling insulin resistance, hyperlipidemia, hypertension and hepatic steatosis in NAFLD patients.

TRIAL REGISTRATION

The clinical trial was registered in the Iranian Clinical Trial Registration Center (IRCT20190731044392N1). https://irct.behdasht.gov.ir/trial/61413 . (The registration date: 30/03/2022).

Association between birth weight and insulin resistance in US adolescents: A retrospective cohort study exploring the role of concurrent body mass index

BACKGROUND AND AIMS

This study aimed to investigate the association between birth weight (BW) and abnormal HOMA-IR in US adolescents aged 12-15 years. The role of concurrent body mass index (BMI) in adolescence was also examined.

METHODS AND RESULTS

This retrospective cohort study included 3429 participants from NHANES with data in 1999-2020. HOMA-IR ≥2.3 was considered abnormal. Participants were classified as low (LBW; <2.5 kg), normal (NBW; 2.5-4.0 kg), or high (HBW; >4.0 kg) BW. Logistic regression was used to explore the association between BW and HOMA-IR. Mediation analysis was used to examine whether BMI z-score in adolescence mediated the association between BW and HOMA-IR. Compared with those in NBW, the odds ratios (95 % CI) of abnormal HOMA-IR in LBW and HBW groups were 1.26 (0.99-1.60), and 0.62 (0.47-0.83) respectively. The association between BW and abnormal HOMA-IR was consistent in all subgroups with no significant interactions. Mediation analysis showed that BW is associated with lower risk of HOMA-IR directly, but with higher risk indirectly via BMI in adolescence.

CONCLUSION

There was a negative linear relationship between BW and the prevalence of abnormal HOMA-IR in adolescents aged 12-15 independent of concurrent BMI. Children who were born with LBW but had high BMI in adolescence were of particularly higher risk of insulin resistance.

Epicardial fat and insulin resistance in healthy older adults: a cross-sectional analysis

Insulin resistance (IR) and cardiovascular diseases (CVD) are relevant concerns in the elderly population; as the world's population ages, IR and CVD are two universal public health problems. While a link between IR a CVD has been established, the mediating mechanisms are uncertain and rigorous investigations are needed to fully elucidate them. The study aimed at assessing the relationship between epicardial fat (EF), an indicator of cardiovascular risk, and IR in Italian free-living elderly (n = 89). Baseline data from a previous cohort was used. Anthropometric measurements, EF, and IR-related variables, including the HOMA-IR index and other biochemical parameters were obtained. The correlation between EF and IR was explored. Further analysis was conducted to identify significant differences regarding IR variables among EF quartiles. EF correlated positively with glucose levels in females, males and the total population. The pairwise comparison among EF quartiles showed significant differences in glucose levels, HOMA-IR index, triglycerides, and total cholesterol levels. To our knowledge, this is the only study assessing the relationship between EF and IR in healthy elderly, while most of the studies have investigated EF and IR in diseased populations. Further research with a longitudinal approach should be conducted to design concrete conclusions about this relationship.

Prediction of Early Kidney Transplant Graft Outcome: Insulin Resistance Index

BACKGROUND

New-onset diabetes after transplantation and increased insulin resistance have both been shown to affect graft performance and survival after kidney transplantation. Thus, we aimed to evaluate the predictive roles of different insulin resistance indices on early graft function in kidney transplant recipients.

MATERIALS AND METHODS

We conducted a retrospective analysis of non-diabetic patients who received kidney transplantation between January 1, 2018 and December 31, 2021. The primary outcome was the predictive role of different insulin resistance indices on early graft function of serum creatinine level and estimated glomerular filtration rate at 1, 3, 6, and 12 months. The secondary outcome analyzed was the possible clinical predictive factors for poor kidney graft function at 12 months.

RESULTS

Among 123 kidney transplantation patients, stratification with homeostatic model assessment for insulin resistance showed no significant difference in kidney graft function outcome at 1, 3, 6, and 12 months. However, patients with a higher insulin-to-glucose ratio exhibited a significantly higher serum creatinine level at 3 and 6 months and a significantly lower estimated glomerular filtration rate level at 3, 6, and 12 months. Using multivariate logistic regression analysis, patients with a higher insulin-to-glucose ratio were associated with a poorer kidney graft function 12 months after transplantation.

CONCLUSION

Patients with a higher baseline insulin resistance with an insulin-to-glucose ratio ≥of 0.092 exhibited a significantly worse early kidney graft function. Thus, with the identification of patients with increased insulin resistance, early intervention, and preventive measures can be implemented to enhance graft performance further.

The Phenotypic Characterization of the Oldest Italian Man from December 28, 2020, to September 23, 2021, A.T., Strengthens the Idea That the Immune System can Play a Key Role in the Attainment of Extreme Longevity

In this paper, we present demographic, clinical, anamnestic, cognitive, and functional data, as well as haematological, haematochemical, immunological, and genetic parameters of an exceptional individual: A.T., a semi-supercentenarian who held the title of the oldest living Italian male centenarian from 28 December 2020, to 23 September 2021. The purpose of this study is to provide fresh insights into extreme phenotypes, with a particular focus on immune-inflammatory parameters. To the best of our knowledge, this study represents the first phenotypic investigation of a semi-supercentenarian, illustrating both INFLA-score, a metric designed to assess the cumulative impact of inflammatory markers and indicators of age-related immune phenotype (ARIP), recognized as significant gauges of biological ageing. The aim of this study was, indeed, to advance our understanding of the role of immune-inflammatory responses in achieving extreme longevity. The results of laboratory tests, as well as clinical history and interview data, when compared to the results of our recent study on Sicilian centenarians, demonstrate an excellent state of health considering his age. Consistent with previous studies, we observed increased IL-6 inflammatory markers and INFLA score in A.T. More interestingly, the semi-supercentenarian showed values of ARIP indicators such as naïve CD4+ cells, CD4+/CD8+ ratio, and CD4+TN/TM ratio in the range of young adult individuals, suggesting that his immune system's biological age was younger than the chronological one. The results support the notion that the immune system can play a role in promoting extreme longevity. However, this does not rule out the involvement of other body systems or organs in achieving extreme longevity.

High dietary intake of unsaturated fatty acids is associated with improved insulin resistance - a cross-sectional study based on the NHANES database

BACKGROUND

A moderate intake of unsaturated fatty acids (UFA) is associated positively with improved insulin resistance. The aim of this study was to investigate the relationship between the dietary intake of unsaturated fatty acids/total fats (UFA/TF) and insulin resistance.

METHODS

15,560 participants were selected from the National Health and Nutrition Examination Survey (NHANES) database enrolled between March 2017 and 2020, and excluded those under 20 years of age, pregnant, or with missing data for key research items. Finally, 7,630 participants were included in the study. R software was used for data analysis that included: (1) general descriptive statistics; (2) comparison of differences in baseline information of three UFA/TF groups, namely low, medium, and high ratios; (3) calculation of the correlation between the UFA/TF ratio and markers of insulin resistance: triglyceride-glucose index (TyG) and homeostatic model assessment for insulin resistance (HOMA-IR); (4) stratification of the study subjects into two groups, with or without insulin resistance, using a cut-off value of HOMA-IR ≥ 2, followed by logistic regression analysis to examine the relationship between UFA/TF and insulin resistance status in the two groups; and (5) further stratification of the subjects according to age, gender, body mass index (BMI), race, total energy intake, total protein, total carbohydrate, total sugars, total dietary fiber, total fat, alcohol consumption, diabetes, hypercholesterolemia to analyze the impact of UFA/TF on insulin resistance status in different subgroups.

RESULTS

(1) A high UFA/TF level was associated with a low TyG index and HOMA-IR [β (vs. TyG index) = -0.559, 95% CI: (-0.821~-0.297), P < 0.001; β (vs. HOMA-IR) = -0.742, 95% CI: (-1.083~-0.402), P < 0.001]. This negative relationship became more pronounced when UFA/TF exceeded 57.9% (i.e., the higher group). (2) Logistic regression analysis showed that a higher UFA/TF level was associated with a lower risk of developing insulin resistance [Q3 vs. Q1: 0.838 (95%CI: 0.709 ~ 0.991); P for trend = 0.038]. After adjusting for covariates such as gender, age, and BMI, this protective effect remained significant (P value < 0.05). (3) Analysis also showed that increased UFA/TF intake reduced the risk of developing insulin resistance (OR = 0.266, 95% CI: (0.075 ~ 0.946), P = 0.041). Subgroup analysis showed that although elevated UFA/TF intake showed no statistically significant difference in its effect in most subgroups, the large study population in this study provides valuable insights on potential changes. Increased UFA/TF intake may confer relatively greater benefits within specific subgroups, particularly among the elderly [Q3 age group, OR = 0.114, 95%CI: (0.012 ~ 1.078), P = 0.058], females [OR = 0.234, 95%CI: (0.041 ~ 1.333), P = 0.102], those with a BMI ≤ 25 kg/m²[OR = 0.191, 95%CI: (0.016 ~ 2.344), P = 0.196], and individuals without hypercholesterolemia [OR = 0.207, 95%CI: (0.042 ~ 1.013), P = 0.0519]. The impact of high UFA/TF levels within subgroups based on the presence or absence of coronary heart disease and stroke displayed contrasting trends. In those without coronary heart disease, there was a significant protective effect against insulin resistance [OR = 0.254, 95% CI: (0.07 ~ 0.929), P = 0.0384], while in the stroke subgroup, a significantly protective effect against insulin resistance was observed [OR = 0.002, 95%CI: (0 ~ 0.695), P = 0.0376].

CONCLUSION

A high dietary intake of UFA relative to total fat consumption could be a protective factor against the risk of developing insulin resistance.

Examining the associations between testosterone and biomarkers as men age

OBJECTIVES

Testosterone concentrations in men decline with advancing age. However, the cause of the decline is yet to be fully elucidated. Therefore, the aims of this study were to examine the associations between chronic diseases such as obesity and type 2 diabetes mellitus (T2DM) with total testosterone (TT) and sex hormone-binding globulin (SHBG), using a large nationally-representative data set (National Health and Nutrition Examination Survey; NHANES).

METHODS

NHANES is a cross-sectional survey, physical examination, and laboratory evaluation of a nationally-representative sample of a non-institutionalized United States population. Male participants aged ≥18 years during the NHANES 2013-2014 and NHANES 2015-2016 survey periods were selected for this analysis. The analysis included the following data: body mass index (BMI), oral glucose tolerance test (OGTT), homeostatic model assessment of insulin resistance (HOMA-IR), insulin, glucose, and age.

RESULTS

An overweight or obese condition was significantly inversely associated with TT and SHBG, even after adjusting for other variables. Several variables associated with T2DM (OGTT, HOMA-IR, insulin, and glucose) were also inversely associated with TT; however, only the associations between OGTT and insulin with TT remained significant after adjusting for the other variables. Insulin and HOMA-IR levels were significantly inversely associated with SHBG; however, only the association between SHBG and pre-diabetic HOMA-IR levels remained significant after adjusting for the other variables. OGTT became significantly associated with SHBG after adjusting for the other variables. Age was significantly inversely associated with TT, but positively associated with SHBG, even after adjusting for other variables.

CONCLUSION

The results of the present study, which is the largest to date, indicate that a marker of obesity, BMI, and some markers of T2DM are both independently and significantly inversely associated with TT and SHBG.

Glycated Hemoglobin Is Suboptimal for the Screening of Prediabetes and Type 2 Diabetes in Adults With Nonalcoholic Fatty Liver Disease

OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) is a risk factor for type 2 diabetes (T2D), but T2D screening tests are not well validated in this population. In this study, we assessed performance of glycated hemoglobin (A1C) and fasting plasma glucose (FPG) in glucose dysmetabolism screening and aimed to optimize detection thresholds for individuals with NAFLD.

METHODS

We retrospectively included oral glucose tolerance tests (OGTTs) from consecutive patients undergoing a specialized clinic for NAFLD, if A1C and/or fasting glucose was available within 3 months of OGTT. We compared performances of A1C and fasting glucose with the "gold standard" of OGTT using thresholds from the 2018 Diabetes Canada guidelines. A1C and FPG thresholds were optimized for detection of glucose dysmetabolism using receiver operating characteristic curves.

RESULTS

We included 63 OGTTs from individuals with NAFLD (52% female, age 48 [interquartile range 35 to 63] years, body mass index 34 [interquartile range 29 to 40] kg/m2). A1C had 16% (95% confidence interval [CI] 6% to 38%) sensitivity (Se) and 97% (95% CI 85% to 100%) specificity (Sp) for T2D detection, and 45% (95% CI 30% to 62%) Se and 100% (95% CI 83% to 100%) Sp for abnormal blood glucose detection. FPG had 67% (95% CI 45% to 83%) Se and 100% (95% CI 92% to 100%) Sp for T2D detection, and 74% (95% CI 59% to 85%) Se and 92% (95% CI 74% to 99%) Sp for abnormal blood glucose detection. Optimal A1C and FPG thresholds were 5.6% and 6.3 mmol/L for T2D detection, which are lower than current recommendations.

CONCLUSIONS

A1C is less sensitive than FPG and is suboptimal for T2D detection, suggesting that OGTT may be obtained if A1C is ≥5.6% or FPG is ≥6.3 mmol/L in individuals with NAFLD, to avoid underdiagnosis and treatment inertia.

The Effect of Fenugreek in Type 2 Diabetes and Prediabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Fenugreek is a widely used herbal medicine as a complementary therapy for diabetes mellitus. Lots of clinical trials have proved its beneficial effect on glycemic control parameters and lipid profiles. Thus, we conducted a systematic review and meta-analysis to evaluate the effectiveness and safety of fenugreek as a treatment for type 2 diabetes mellitus. We searched PubMed, Embase, Cochrane, China Knowledge Resource Integrated Database (CNKI), Korean studies Information Service System (KISS), Research Information Sharing Service (RISS), and ScienceON to select RCTs which used fenugreek targeting hyperglycemia with a control group. We used either a random effect model or a fixed model in a meta-analysis of Fasting blood glucose (FBG), 2 h plasma glucose during a 75 g oral glucose tolerance test (OGTT) (2-hPG), homeostatic model assessment for insulin resistance (HOMA-IR), glycosylated hemoglobin (HbA1c)/total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL-C), low density lipoprotein (LDL-C), body mass index (BMI). After screening, a total of 10 studies (706 participants) remained. Fenugreek significantly reduced FBG, 2-hPG, and HbA1c, but it did not significantly decrease HOMA-IR. Moreover, it significantly improved TC, TG, and HDL-C, while there were no significant differences in LDL-C and BMI. Hepatic or renal toxicity was not observed, and there were no severe adverse events associated with fenugreek despite mild gastrointestinal side effects in some studies. In conclusion, fenugreek improves overall glycemic control parameters and lipid profile safely.

Association of HDL Subfraction Profile with the Progression of Insulin Resistance

Type 2 diabetes mellitus (T2DM) is a major global public health problem, as it is associated with increased morbidity, mortality, and healthcare costs. Insulin resistance (IR) is a condition characterized by disturbances in carbohydrate and lipid metabolism that precedes T2DM. The aim of the present study was to investigate the association between HDL and its subfraction profile and the progression of IR, as assessed by the Homeostatic Model Assessment for IR (HOMA-IR) index, and to define cut-off values to identify an increased risk of IR. Individuals with a HOMA-IR greater than 3.63 were considered to have IR. The HDL subfractions were separated using the Lipoprint system, which identifies ten subfractions (HDL-1-10) in three subclasses as large (HDL-L), intermediate (HDL-I) and small (HDL-S). Analyses were performed on samples from 240 individuals without IR and 137 with IR from the Hungarian general and Roma populations. The HDL-1 to -6 subfractions and the HDL-L and -I classes showed a significant negative association with the progression and existence of IR. Among them, HDL-2 (B = -40.37, p = 2.08 × 10-11) and HDL-L (B = -14.85, p = 9.52 × 10-10) showed the strongest correlation. The optimal threshold was found to be 0.264 mmol/L for HDL-L and 0.102 mmol/L and above for HDL-2. Individuals with HDL-L levels below the reference value had a 5.1-fold higher risk of IR (p = 2.2 × 10-7), while those with HDL-2 levels had a 4.2-fold higher risk (p = 3.0 × 10-6). This study demonstrates that the HDL subfraction profile (especially the decrease in HDL-2 and -L) may be a useful marker for the early detection and intervention of atherogenic dyslipidemia in subjects with impaired glucose and insulin metabolism.

Plasma Lipids Profile in the Prediction of Non-Alcoholic Steatohepatitis in Adults: A Case-Control Study

Patients with non-alcoholic steatohepatitis (NASH) show significantly faster progress in the stages of fibrosis compared to those with non-alcoholic fatty liver (NAFL) disease. The non-invasive diagnosis of NASH remains an unmet clinical need. Preliminary data have shown that sphingolipids, especially ceramides, fatty acids, and other lipid classes may be related to the presence of NASH and the histological activity of the disease. The aim of our study was to assess the association of certain plasma lipid classes, such as fatty acids, acylcarnitines, and ceramides, with the histopathological findings in patients with NASH. The study included three groups: patients with NASH (N = 12), NAFL (N = 10), and healthy [non non-alcoholic fatty liver disease (NAFLD)] controls (N = 15). Plasma samples were collected after 12 h of fasting, and targeted analyses for fatty acids, acylcarnitines, and ceramides were performed. Baseline clinical and demographic characteristics were collected. There was no significant difference in baseline characteristics across the three groups or between NAFL and NASH patients. Patients with NASH had increased levels of several fatty acids, including, among others, fatty acid (FA) 14:0, FA 15:0, FA 18:0, FA 18:3n3, as well as Cer(d18:1/16:0), compared to NAFL patients and healthy controls. No significant difference was found between NAFL patients and healthy controls. In conclusion, patients with NASH exhibited a distinctive plasma lipid profile that can differentiate them from NAFL patients and non-NAFLD populations. More data from larger cohorts are needed to validate these findings and examine possible implications for diagnostic and management strategies of the disease.

Nanopore Sequencing of RAGE Gene Polymorphisms and Their Association with Type 2 Diabetes

The receptor for advanced glycation end products (RAGE) is a transmembrane protein that interacts with its ligands, advanced glycation end products (AGEs). AGEs are elevated in diabetes and diabetic complications, leading to increased oxidative stress and activation of pro-inflammatory pathways facilitated by AGE-RAGE signaling. Polymorphisms in the RAGE gene can potentially affect AGE-RAGE interaction and its downstream signaling, which plays a crucial role in the progression of diabetes and its complications. In this study, we used nanopore sequencing for genotyping of RAGE polymorphism and identified a maximum number of 33 polymorphisms, including two previously unreported novel mutations in a cohort of healthy, type 2 diabetics without nephropathy and type 2 diabetics with nephropathy in order to identify associations. Two novel RAGE polymorphisms in the intron 8 and 3'UTR region at genomic locations 32181834 and 32181132, respectively, were detected with a low frequency. For four previously reported polymorphisms, cross-validation by PCR-RFLP showed 99.75% concordance with nanopore sequencing. Analysis of genotype distribution and allele frequencies revealed that five single nucleotide polymorphisms, i.e., rs1800625, rs3131300, rs3134940, rs2070600, and rs9391855, were associated with an increased risk for type 2 diabetes.

HOMA-IR mean values in healthy individuals: a population-based study in iranian subjects

Purpose

Homeostasis Model Assessment-estimated Insulin Resistance (HOMA-IR) is an important indicator of insulin resistance. In this population-based investigation, we sought to report the mean value of HOMA-IR in different subgroups of a large population-based database of Iranian healthy subjects.

Methods

This study recruited adult healthy individuals between the ages of 18 to 70 years old to Massoud Medical Laboratory, Tehran, Iran. Fasting insulin was measured by using the Electro Chemiluminescence method using Roche Cobas 6000 e601/602 instrument.

Results

The mean ± SD value of the HOMA-IR index in the studied population was 2.11 ± 0.99 (2.5-97.5% percentiles: 0.66-4.50). In addition, the mean ± SD of HOMA-IR index in male and female groups were 2.35  1.0 (2.5-97.5 percentile: 0.57-4.37) and 2.05 ± 1.0 (2.5-97.5 percentiles: 0.53-4.35), respectively. Interestingly, it was observed a significant increment for the HOMA-IR index in the male group compared with the female group in all age subgroups (P < 0.01).

Conclusions

Our findings showed the mean value of 2.11 ± 0.99 HOMA-IR in the Iranian healthy population. Considering the large sample size in our study, more clinical investigations in terms of ethnicity should be done to provide a precise standardized HOMA-IR index in the Iranian population.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-022-01099-9.

Controversial Impact of Vitamin D Supplementation on Reducing Insulin Resistance and Prevention of Type 2 Diabetes in Patients with Prediabetes: A Systematic Review

BACKGROUND

Prediabetes has become a worldwide health problem. Multiple clinical trials have been conducted to determine the potential benefits of vitamin D supplementation in preventing the conversion to diabetes, but the results are inconsistent. The aims of this study were to evaluate the current knowledge and to suggest recommendations for researchers on designing future trials regarding that matter.

METHODS

Four databases were searched for randomized control trials from the last 10 years about vitamin D and insulin resistance. The systematic electronic literature search identified 2645 studies, of which thirty-eight qualified for full-text reading and discussion. Finally, eight trials were included.

RESULTS

Final results of seven trials reported that supplementation of vitamin D does not reduce insulin resistance nor reduces the risk of diabetes mellitus type 2 development in prediabetes. Only one trial showed improvements in fasting glucose and HOMA-IR.

CONCLUSIONS

Due to the great variation and biases in study designs, an unambiguous interpretation of the results is not possible. To eliminate those vulnerabilities in the future, we made certain suggestions for study design. Long-term and well-designed studies are still required.

Prediction of subclinical atherosclerosis in low Framingham risk score individuals by using the metabolic syndrome criteria and insulin sensitivity index

Background

Subclinical atherosclerosis can be present in individuals with an optimal cardiovascular risk factor profile. Traditional risk scores such as the Framingham risk score do not adequately capture risk stratification in low-risk individuals. The aim of this study was to determine if markers of metabolic syndrome and insulin resistance can better stratify low-risk individuals.

Methods

A cross-sectional study of 101 healthy participants with a low Framingham risk score and no prior morbidities was performed to assess prevalence of subclinical atherosclerosis using computed tomography (CT) and ultrasound. Participants were compared between groups based on Metabolic Syndrome (MetS) and Insulin-Sensitivity Index (ISI-cal) scores.

Results

Twenty three individuals (23%) had subclinical atherosclerosis with elevated CT Agatston score ≥1. Presence of both insulin resistance (ISI-cal <9.23) and fulfillment of at least one metabolic syndrome criterion denoted high risk, resulting in significantly improved AUC (0.706 95%CI 0.588–0.822) over the Framingham risk score in predicting elevated CT Agatston score ≥1, with net reclassification index of 50.9 ± 23.7%. High-risk patients by the new classification also exhibited significantly increased carotid intima thickness.

Conclusions

The overlap of insulin resistance and presence of ≥1 criterion for metabolic syndrome may play an instrumental role in identifying traditionally low-risk individuals predisposed to future risk of atherosclerosis and its sequelae.

The Effect of Commonly Used Fixed-Dose Single Pill Combinations of Renin-Angiotensin-System Blockers and Calcium Channel Blockers on HOMA-IR Index in Hypertensive Patients with Impaired Fasting Glucose: a 12-Week Randomized Open-Label Prospective Study

Backround: The effect of antihypertensive drugs on glucose homeostasis and insulin resistance remains an issue under investigation. There is evidence that renin-angiotensin system (RAS) blockers may favorably affect glucose metabolism, while treatment with calcium channel blockers (CCBs) is considered to have an overall neutral metabolic effect. However, the effects on glycemic indices may differ among agents within the same class of antihypertensive drugs. Objective: To evaluate the effects of different fixed-dose single pill combinations of RAS blockers with CCBs on homeostatic model assessment for insulin resistance (HOMA-IR). Methods:Drug-naive patients with arterial hypertension (AH) and impaired fasting glucose (IFG) were randomly allocated to open-label fixed, single pill combinations of valsartan 160 mg/day plus amlodipine 5 mg/day (VAL/AMLO group, n = 54), delapril 30 mg/day and manidipine 10 mg/day (DEL/MANI group, n = 53) or telmisartan 80 mg/day and amlodipine 5 mg/day (TEL/AMLO group, n = 51) for 12 weeks. Glycemic indices and HOMA-IR were determined at baseline and post-treatment. Results:A total of 158 patients were included. All treatment combinations effectively reduced blood pressure (systolic and diastolic) to similar levels (all p < 0.001). A decrease in the HOMA-IR index by 22.55% (p <0.01) was noted following treatment with TEL/AMLO, while an increase by 1.4% (p = 0.57) and 12.65% (p = 0.072) was observed in the VAL/AMLO group and the DEL/MANI group, respectively. These changes were significantly different between TEL/AMLO and DEL/MANI (p < 0.05) as well as between TEL/AMLO and VAL/AMLO (p < 0.001). Conclusion:Despite similar antihypertensive action, the effect of fixed, single pill combinations with TEL/AMLO, VAL/AMLO and DEL/MANI on insulin resistance is in favor of TEL/AMLO. Trial registration: The study protocol was published online in https://diavgeia.gov.gr/ (No: ÂÈ6Ó46906Ç-ÁÅÓ) via the Ministry of Digital Governance, after receiving approval from the Scientific Council and Administrative Council of University Hospital of Ioannina (No. of approval: 1/12-06-2014 (issue 150). https://diavgeia.gov.gr/decision/view/%CE%92%CE%986%CE%A346906%CE%97- %CE%91%CE%95%CE%A3 h t t p s : / / d i a v g e i a . g o v . g r / d o c / % C E % 9 2 % C E % 9 8 6 % C E % A 3 4 6 9 0 6 % C E % 9 7 - %CE%91%CE%95%CE%A3?inline=true.

Genetic Susceptibility to Insulin Resistance and Its Association with Estimated Longevity in the Hungarian General and Roma Populations

Diabetes mellitus is a major public health problem with a wide range of prevalence among different ethnic groups. Early recognition of pre-diabetes is important to prevent the development of the disease, its complications, co-morbidities, and consequently early death. Insulin resistance (IR) is considered a condition that precedes type 2 diabetes; thus, understanding its underlying causes (genetic and non-genetic factors) will bring us closer to preventing it. The present study aimed to investigate the genetic susceptibility to IR and its impact on estimated longevity in populations with different ethnic origins using randomly selected samples of 372 Hungarian general (HG, as a reference with Caucasian origin) and 334 Roma participants (largest ethnic minority in Europe, with a northern India origin). In the present study, we used the Homeostasis Model Assessment—Insulin Resistance (HOMA—IR) to identify people with IR (>3.63) at the population level. To investigate the genetic predisposition to IR, 29 single nucleotide polymorphisms (SNPs) identified in a systematic literature search were selected and genotyped in sample populations. In the analyses, the adjusted p < 0.0033 was considered significant. Of these 29 SNPs, the commutative effects of 15 SNPs showing the strongest association with HOMA—IR were used to calculate an optimized genetic risk score (oGRS). The oGRS was found nominally significantly (p = 0.019) higher in the Roma population compared to HG one, and it was more strongly correlated with HOMA—IR. Therefore, it can be considered as a stronger predictor of the presence of IR among the Roma (AUCRoma = 0.673 vs. AUCHG = 0.528). Furthermore, oGRS also showed a significant correlation with reduced estimated longevity in the Roma population (β = −0.724, 95% CI: −1.230−−0.218; p = 0.005), but not in the HG one (β = 0.065, 95% CI: −0.388−0.518; p = 0.779). Overall, IR shows a strong correlation with a genetic predisposition among Roma, but not in the HG population. Furthermore, the increased genetic risk of Roma is associated with shorter estimated longevity, whereas this association is not observed in the HG one. Increased genetic susceptibility of Roma to IR should be considered in preventive programs targeting the development of type 2 diabetes, which may also reduce the risk of preventable premature death among them.

Shift work and insulin resistance (HOMA-IR) among professional drivers

BACKGROUND: Shift work may be associated with insulin resistance. OBJECTIVE: This study aimed to investigate the potential association between shift work and the homeostatic model assessment of insulin resistance (HOMA-IR) index in professional drivers. METHOD: A total of four hundred fifty-three professional drivers were invited to participate in the study within a periodic medical examination in the occupational setting. One hundred seventy-seven daytime workers were compared with 175 night shifts and 101 early morning shift drivers. Demographic, occupational, and medical examination including blood pressure, anthropometric data was assessed. Measurement of serum insulin, fasting blood glucose and lipid profile were done for all drivers. RESULTS: Compared with day workers, night shift and early morning shift drivers displayed higher levels of HOMA-IR. Metabolic syndrome was found to be significantly increased in night workers. In linear regression analysis, insulin resistance was correlated with shift work independently of demographic and occupational characteristics. CONCLUSION: The study revealed that shift work could be a risk factor in developing the risk of metabolic syndrome and insulin resistance. Suggestively, health strategies such as structured lifestyle counseling in occupational health settings are warranted to improve and modify cardiometabolic risk factors.

Profiling the Skeletal Muscle Proteome in Patients on Atypical Antipsychotics and Mood Stabilizers

Atypical antipsychotics (AAP) are used in the treatment of severe mental illness. They are associated with several metabolic side effects including insulin resistance. The skeletal muscle is the primary tissue responsible for insulin-stimulated glucose uptake. Dysfunction of protein regulation within the skeletal muscle following treatment with AAPs may play a role in the associated metabolic side effects. The objective of this study was to measure protein abundance in the skeletal muscle of patients on long-term AAP or mood stabilizer treatment. Cross-sectional muscle biopsies were obtained from patients with bipolar disorder and global protein abundance was measured using stable isotope labeling by amino acid (SILAC) combined with high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Sixteen patients completed muscle biopsies and were included in the proteomic analyses. A total of 40 proteins were significantly different between the AAP group and the mood stabilizer group. In-silico pathway analysis identified significant enrichment in several pathways including glucose metabolism, cell cycle, apoptosis, and folate metabolism. Proteome abundance changes also differed based on protein biological processes and function. In summary, significant differences in proteomic profiles were identified in the skeletal muscle between patients on AAPs and mood stabilizers. Future work is needed to validate these findings in prospectively sampled populations.

DNA methylation of circadian genes and markers of cardiometabolic risk in female hospital workers: An exploratory study

Night shift work has been linked to increased risk of cardiovascular disease (CVD); however, the underlying mechanisms remain unclear. A compelling yet understudied mechanism involves differential DNA methylation of circadian genes. To investigate the relevance of this mechanism, we conducted an exploratory cross-sectional study of 74 female hospital personnel (38 day workers, 36 night shift workers). Sociodemographic, lifestyle, and health characteristics as well as shift work status and history were determined through self-report. Fasting blood samples were collected to measure markers of cardiometabolic risk and DNA was extracted to measure DNA methylation of 1150 cytosine-guanine (CpG) sites across 22 circadian genes. Associations between methylation levels at individual CpG sites (β-values) and markers of cardiometabolic risk were analyzed while considering effect modification by shift work status. The false discovery rate was applied to account for multiple comparisons (q ≤ 0.20). Two CpG sites [cg06758649 (CRY1) and cg06899802 (CSNK1A1)] were differentially associated with waist circumference and body mass index by shift work status, and eight CpG sites [cg26103512 (CSNK1D), cg03941313 (CSNK1E), cg18217763 (CSNK1E), cg16682686 (DEC1), cg12061096 (RORA), cg10133825 (RORA), cg19652148 (RORA), and cg22904654 (RORA)] were differentially associated with LDL cholesterol concentration by shift work status (all q ≤ 0.20). Our findings suggest that the relationship between DNA methylation of circadian genes and cardiometabolic risk differs by day and night shift worker status, which may contribute to mechanisms of increased risk of CVD observed among night shift workers.

Development and Validation of an Insulin Resistance Predicting Model Using a Machine-Learning Approach in a Population-Based Cohort in Korea

Background: Insulin resistance is a common etiology of metabolic syndrome, but receiver operating characteristic (ROC) curve analysis shows a weak association in Koreans. Using a machine learning (ML) approach, we aimed to generate the best model for predicting insulin resistance in Korean adults aged > 40 of the Ansan/Ansung cohort using a machine learning (ML) approach. Methods: The demographic, anthropometric, biochemical, genetic, nutrient, and lifestyle variables of 8842 participants were included. The polygenetic risk scores (PRS) generated by a genome-wide association study were added to represent the genetic impact of insulin resistance. They were divided randomly into the training (n = 7037) and test (n = 1769) sets. Potentially important features were selected in the highest area under the curve (AUC) of the ROC curve from 99 features using seven different ML algorithms. The AUC target was ≥0.85 for the best prediction of insulin resistance with the lowest number of features. Results: The cutoff of insulin resistance defined with HOMA-IR was 2.31 using logistic regression before conducting ML. XGBoost and logistic regression algorithms generated the highest AUC (0.86) of the prediction models using 99 features, while the random forest algorithm generated a model with 0.82 AUC. These models showed high accuracy and k-fold values (>0.85). The prediction model containing 15 features had the highest AUC of the ROC curve in XGBoost and random forest algorithms. PRS was one of 15 features. The final prediction models for insulin resistance were generated with the same nine features in the XGBoost (AUC = 0.86), random forest (AUC = 0.84), and artificial neural network (AUC = 0.86) algorithms. The model included the fasting serum glucose, ALT, total bilirubin, HDL concentrations, waist circumference, body fat, pulse, season to enroll in the study, and gender. Conclusion: The liver function, regular pulse checking, and seasonal variation in addition to metabolic syndrome components should be considered to predict insulin resistance in Koreans aged over 40 years.

HOMA-IR index in non-diabetic patient, a reliable method for early diagnosis of liver steatosis

Background

NAFLD is one of the most common liver diseases in the world. HOMA-IR as an indicator of insulin resistance is commonly used in clinical trials in NAFLD patients. The aim of this study was to evaluate the application of HOMA-IR index in the diagnosis of NAFLD.

Methods

This study was performed on 54 patients with NAFLD and 54 non-NAFLD patients that referred to Razi Hospital in Rasht during 2019-2020. FibroScan was used to diagnose NAFLD in the patient group and ultrasound was used to rule it out in the control group. Metabolic and hepatic parameters were measured for each patient. Data were entered into SPSS 22 software and the necessary analyses were performed.

Results

The mean age of the subjects in the study was 44.01±13.12 years and ranged from 18 to 75 years. 72.2% of people affected by NAFLD were men (p <0.001) .The optimal cut-off point for HOMA-IR in NAFLD was 1.65 with a sensitivity of 89.7% and a specificity of 76.9% in men and 1.90 with a sensitivity of 86.7% and a specificity of 82.9% in women. Overall, the optimal cut-off point for HOMA-IR in NAFLD was 1.75 with a sensitivity of 87.0% and a specificity of 81.5%. In addition, the results showed that there was no significant relationship between steatosis and hepatic fibrosis with HOMA-IR index.

Conclusion

The results showed that HOMA-IR can be used as a reliable criterion for early detection of NAFLD.

Cholesterol and glucose profiles according to different fasting C-peptide levels: a cross-sectional analysis in a healthy cohort from the Czech Republic

The relationship between glycaemia and lipoprotein metabolism has not been completely clarified, and slight differences may be found between local authors, trials and evaluated parameters. Therefore this cross-sectional study investigated fasting cholesterol and glucose levels along with the determination of atherogenic index in a cohort of healthy individuals from the Czech Republic in relation to their fasting C-peptide levels. Data were collected between 2009 and 2018 and a total of 3189 individuals were stratified by C-peptide reference range (260-1730 pmol/l) into three groups - below (n = 111), within (n = 2952) and above (n = 126). Total, HDL, LDL cholesterol and atherogenic index were used to compare lipoprotein levels by relevant C-peptide concentrations. Participants using the supplements to affect lipid or glycaemia metabolism were excluded from this study. The evaluation of blood parameters in a fasting state included correlations between C-peptide and cholesterols, differences of variances (F-test) and the comparison of lipoprotein mean values (t-test) between the groups created by the C-peptide reference range. Mean values of total (4.9, 5.1, 5.3 mmol/l), LDL (2.6, 3.1, 3.4 mmol/l) cholesterol and atherogenic index (2.1, 2.8, 3.7) were higher with increasing C-peptide levels, whereas HDL was inversely associated with fasting C-peptide concentration. A positive and negative correlation between atherogenic index (rxy = 0.36) and HDL level (rxy = -0.36) with C-peptide values was found. Differences of HDL, LDL and atherogenic index were, in particular, recorded between the groups below and above the reference range of C-peptide (p ≤ 0.001). Considerable differences (p ≤ 0.001) were also observed for the same lipoprotein characteristics between the groups above and within the C-peptide reference. Generally, the type of cholesterol is crucial for the evaluation of specific changes concerning the C-peptide range. Lipoprotein concentrations differ in relation to C-peptide - not only below and above the physiological range, but also inside and outside of it. Conclusions: Fasting levels of cholesterol, plasma glucose, and atherogenic index were strongly associated with fasting C-peptide levels in healthy individuals. Our data suggest that fasting C-peptide could serve as a biomarker for the early detection of metabolic syndrome and/or insulin resistance prior to the manifestation of type 2 diabetes.

Alterations of glycaemia, insulin resistance and body mass index within the C-peptide optimal range in non-diabetic patients

The study focused on changes or cut-offs of glycaemia, insulin resistance and body mass index within the C-peptide reference range (260-1730 pmol/l). The metabolic profile of individuals in the Czech Republic without diabetes (n = 3186) was classified by whiskers and quartiles of C-peptide into four groups with the following ranges: 290-510 (n = 694), 511-710 (n = 780), 711-950 (n = 720) and 951-1560 pmol/l (n = 673). Fasting levels of glucose, insulin, HOMA IR (Homeostasis Model Assessment for Insulin Resistance) and BMI (body mass index) were compared by a relevant C-peptide range. Participants taking medication to control glycaemia were excluded. The evaluation involved correlations between C-peptides and the above parameters, F-test and t-test. Changes in glucose levels (from 5.3 to 5.6 mmol/l) between the groups were lower in comparison to insulin, which reached relatively greater changes (from 4.0 to 14.2 mIU/l). HOMA IR increased considerably with growing C-peptide concentrations (0.9, 1.5, 2.2 and 3.5) and BMI values showed a similar trend (28.3, 31.0, 33.6 and 37.4). Considerable changes were observed for insulin (5.2 mIU/l, 57.8%) and HOMA IR (1.3, 61.3%) between groups with C-peptide ranges of 711-950 and 951-1560 pmol/l. Although correlations involving C-peptide, insulin, glucose and BMI seemed to be non-significant (up to rxy = 0.25), the mean values of insulin, HOMA IR and BMI showed statistically significant changes between all groups with various C-peptide concentrations (p ≤ 0.001). Generally, most important differences appeared in glucose metabolism and body mass index between C-peptide ranges of 711-950 and 951-1560 pmol/l. Absolute and relative changes of C-peptide concentrations are possible to use for the assessment of glucose regulatory mechanism. The spectrum of investigated parameters could be a useful tool to prevent the risks linked with the alterations of glycaemia.

Phenotyping the Prediabetic Population-A Closer Look at Intermediate Glucose Status and Cardiovascular Disease

Even though the new thresholds for defining prediabetes have been around for more than ten years, there is still controversy surrounding the precise characterization of this intermediate glucose metabolism status. The risk of developing diabetes and macro and microvascular disease linked to prediabetes is well known. Still, the prediabetic population is far from being homogenous, and phenotyping it into less heterogeneous groups might prove useful for long-term risk assessment, follow-up, and primary prevention. Unfortunately, the current definition of prediabetes is quite rigid and disregards the underlying pathophysiologic mechanisms and their potential metabolic progression towards overt disease. In addition, prediabetes is commonly associated with a cluster of risk factors that worsen the prognosis. These risk factors all revolve around a common denominator: inflammation. This review focuses on identifying the population that needs to be screened for prediabetes and the already declared prediabetic patients who are at a higher risk of cardiovascular disease and require closer monitoring.

Anthropometric features in predicting insulin resistance among non-menopausal Indonesian adult females

INTRODUCTION

The prevalence of obesity is increasing worldwide in high, low, and middle-income countries such as Indonesia. Obesity rate is higher in females in Indonesia. Obesity has important contribution in the occurrence of insulin resistance (IR) and type 2 diabetes mellitus. Several anthropometric measurements such as waist circumference (WC), body mass index (BMI), body mass (BM), total body fat percentage (Fat%) and visceral fat (VF) are related to IR. This study aimed to investigate which of those measurements could be used as a better predictor of IR in non-menopausal Indonesian adult females.

METHODS

Total of 80 non-menopausal Indonesian adult females ranging from 21 to 40 years were recruited in this study. Insulin resistance was measured by using Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) equation. Subjects with HOMA-IR index >75th percentile with cut-off 2.74 were defined as IR. Waist circumference, BMI and BM were measured, while TF and VF were measured by bioelectrical impedance analysis (BIA).

RESULTS

HOMA-IR had significant correlation with WC (r = 0.563, p < 0.001), BMI (r = 0.537, p < 0.001), BM (r = 0.515, p < 0.001), VF (r = 0.515, p < 0.001), Fat% (r = 0.490, p < 0.001). The area under curve of VF (0.809), BMI (0.807), WC (0.805), and BM (0.799) are slightly larger than and Fat% (0.766).

CONCLUSION

Insulin resistance had strong correlation with all anthropometric measurements, but the correlation was less significant with Fat%.

[Effectiveness of the TG/HDL-C ratio to improve GLP-1 prescription in patients with type 2 diabetes in primary care]

AIMS

Check the usefulness of ratio TG/HDL-C≥2.5 to improve the effectiveness of GLP-1 prescribing in patients with type 2 diabetes (DM2) in primary care, and determine whether any patient profile would higher benefit.

DESIGN

Descriptive cross-sectional study.

LOCATION

Barranco Grande Health Center, Tenerife.

PARTICIPANTS

Random selection of patients with DM2 attended by 12 family doctors and 12 nurses.

MAIN MEASUREMENTS

Poor control according to the current criteria was compared to poor control according to the proposed rule. To determine who would benefit, the sociodemographic, clinical, therapeutic and follow-up characteristics were analyzed. Descriptive, bivariate and multivariate statistical analysis was performed.

RESULTS

No predominant characteristics were found in the patients who would be prescribed GLP-1 according to the proposed rule, but those that reached a significance P<.20 were included as potential explanatory factors in a multivariate binary logistic regression model. The adjustment of the model retained the factors of therapeutic non-compliance (OR 3.40 [1.58-5.02]; P=.003), evolution of DM2 less than 15 years (OR 2.74 [1.10-4.89]; P=.031), number of prescribed anti-diabetes drugs (OR 2.30 [1.88-2.81]; P<.001) and age under 65 years (OR 1.67 [1.08-2.58]; P=.021).

CONCLUSIONS

The use of the rule that we propose for the prescription of GLP-1 (2018 recommendations of the GDPS network combined with the TG/HDL-C ratio≥2.5 or BMI≥30kg/m²), instead of the current criterion adopted by the National Health System, would allow to broaden the spectrum of application of the drug in patients with poor control of their DM2.

Index of Cardiac Age Index and Cardiometabolic Biomarkers in Adults with Metabolic Syndrome

Background: The presence of metabolic syndrome (MetS) seems to alter or accelerate the aging process of tissues or organs including the heart. We aim to investigate whether MetS are associated with an index of cardiac age calculated by parameters derived from 128-slice cardiac multidetector computed tomography (MDCT) and cardiometabolic biomarkers in adults. Materials and Methods: In this cross-sectional study, the data were collected from 135 subjects who underwent a comprehensive health checkup, including cardiac MDCT in adults (age ≥18 years). Cardiometabolic biomarkers and an index of cardiac age were measured. Results: Sixty-one (45.2%) had MetS and 44 subjects (32.6%) presented with moderate or severe coronary artery stenosis (CAS) on cardiac MDCT. MetS had positive correlations with several anthropometric variables, metabolic variables [triglyceride, gamma-glutamyl transpeptidase (GGT), homeostatic model assessment of insulin resistance (HOMA-IR)], and systolic blood pressure, cardiac parameters, an index of cardiac age and CAS, whereas had a negative correlation with high-density lipoprotein cholesterol. The diagnostic accuracy for MetS had similar area under the curve among the four variables (index of cardiac age, CAS, HOMA-IR, GGT). On age-adjusted multivariate analysis, only high index of cardiac age (≥55.0 years), and high HOMA-IR (≥1.22) were significantly and independently associated with MetS [odds ratio (OR) 2.48, 95% confidence interval (CI) 1.19-5.18, P = 0.016 and OR 3.41, 95% CI 1.65-7.06, P = 0.001, respectively]. Conclusion: Adults with MetS had higher index of cardiac age and higher HOMA-IR, compared with adults without MetS.

Metabolic syndrome and the risk of cardiovascular complications in young patients with different phenotypes of polycystic ovary syndrome

PURPOSE

Insulin resistance is an important factor in the pathogenesis of polycystic ovary syndrome (PCOS), which is associated with higher risk of metabolic syndrome (MetS) and cardiovascular complications. Early atherosclerotic lesions may be diagnosed by ultrasonographic parameters: brachial artery flow-mediated dilation after reactive hyperaemia (FMD) and intima-media thickness of common carotid artery (IMT). The aim of the study was to assess the relation of IMT and FMD with clinical and laboratory parameters reflecting metabolic status in young women with different PCOS phenotypes.

METHODS

The study included 154 PCOS patients diagnosed with the Rotterdam criteria, divided into four phenotypes, and 113 healthy women. Laboratory analyses, transvaginal ultrasound, and IMT and FMD measurements were conducted. MetS was diagnosed with International Diabetes Federation/American Heart Association (IDF/AHA) consensus criteria.

RESULTS

MetS was more prevalent in PCOS patients than healthy women (14.29 vs. 5.31%; p = 0.019), with highest prevalence in phenotypes I and II (p = 0.039). IMT and FMD did not differ between PCOS patients and the controls, nor between the PCOS phenotypes. PCOS patients with MetS presented lower FMD than other PCOS patients (p = 0.018). In women with PCOS, FMD correlated with glucose and insulin concentrations in the fasting state (R = -0.33, p = 0.002; R = -0.23, p = 0.026) and at 2 h of OGTT (R = -0.29, p = 0.006; R = -0.26, p = 0.014). In patients with phenotype I, correlations were found between IMT and BMI (R = 0.45, p = 0.006) and between FMD and fasting glucose concentrations (R = -0.46, p = 0.011).

CONCLUSIONS

Metabolic disturbances and the diagnosis of MetS in patients with PCOS, especially in hyperandrogenic phenotypes, might be associated with alterations in IMT and FMD.

HOMA-IR in acromegaly: a systematic review and meta-analysis

PURPOSE

This review is aimed at examining whether the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) is higher in Caucasian, adult, treatment-naïve patients with acromegaly (ACRO) than in the reference population independently of diabetes presence and to evaluate the impact of treatment [surgery and somatostatin analogues (SSAs)] on its assessment.

METHODS

We systematically reviewed in PubMed and Web of Science from July 1985 to December 2019, registered with the code number CRD42020148737. The inclusion criteria comprised studies conducted in Caucasian adult treatment-naïve patients with active ACRO in whom HOMA-IR or basal insulin and glucose were reported. Three reviewers screened eligible publications, extracted the outcomes, and assessed the risk of biases.

RESULTS

Of 118 originally selected studies, 15 met the inclusion criteria. HOMA-IR was higher in ACRO than the reference population, with mean difference and (95% confidence intervals) of 2.04 (0.65-3.44), even in ACRO patients without diabetes, 1.89 (1.06-2.73). HOMA-IR significantly decreased after treatment with either surgery or SSAs - 2.53 (- 3.24- - 1.81) and - 2.30 (- 3.05- - 1.56); respectively. However, the reduction of HOMA-IR due to SSAs did not improve basal glucose.

CONCLUSION

HOMA-IR in treatment-naïve ACRO patients is higher than in the reference population, even in patients without diabetes. This finding, confirms that insulin resistance is an early event in ACRO. Our results also suggest that HOMA-IR is not an adequate tool for assessing insulin resistance in those patients treated with SSAs.

Insulin Resistance in Association with Thyroid Function, Psychoemotional State, and Cardiovascular Risk Factors

Background: Individuals with insulin resistance (IR) have a high risk of diabetes or metabolic syndrome, and they are more likely to have depression. Furthermore, IR by itself is a major cardiovascular risk factor in healthy persons. Thus, we aimed to investigate IR in association with thyroid function, psychoemotional state, and cardiovascular risk factors among 45–84-year-old citizens of Palanga. Methods: A randomized epidemiological study was performed with 850 subjects. All participants were evaluated for sociodemographic, clinical, and cardiovascular risk factors and biochemical analysis. IR was evaluated by the homeostasis model assessment of IR (HOMA-IR). Results: All study participants were stratified into groups without IR (HOMA-IR ≤ 2.7) and with IR (HOMA-IR > 2.7). The analysis of parameters between the two study groups showed some statistically significant relationships between IR and cardiovascular risk factors. The predictable accuracy was presented using receiver performance characteristic curves for HOMA-IR scores in women and men separately. If the HOMA-IR score is higher than 3.45, individuals are significantly more likely to have type 2 diabetes mellitus (T2DM). Conclusions: An increase of fasting glucose and more frequent incidence of metabolic syndrome, diabetes, and cardiovascular diseases in subjects with IR are associated with the prevalence of cardiovascular risk factors. There was no significant association between thyroid function and HOMA-IR. HOMA-IR cut-offs could predict the presence of T2DM.

The Changes of Cholesterol Profile at the Different Insulin Resistance Range in the Czech Republic

Background and Objectives: The mechanism of the relationship between glycemia and lipid metabolism has not been completely clarified, and slight differences may be found between authors and the kinds of evaluated parameters. Therefore, this study focused on possible changes of lipoprotein profile with regards to HOMA IR (Homeostatic Model Assessment for Insulin Resistance) cut-off 3.63, considered a signal of glucose metabolism alterations. Materials and Methods: The metabolic profiles of 3051 individuals were divided by HOMA IR values into two groups below cut-off 3.63, including (n = 2627) and above cut-off (n = 424). Patients taking medication or supplements to affect lipid, insulin, or glucose metabolism were excluded. Fasting glucose levels, insulin, and lipoproteins (total, HDL-high density and LDL-low density lipoprotein cholesterol) were compared between the groups with different HOMA IR. After analysis of data distribution, F-test and t-test were provided to compare variances and mean values. Results: The evaluation shows that the kind of cholesterol is crucial for a possible relationship with glucose metabolism and consequently confirms the changes of lipoproteins (HDL and LDL) by HOMA IR cut-off 3.63. Conclusions: The results of patients divided by HOMA IR cut-off 3.63 also suggest possible changes in the regulation of glucose metabolism and lipoprotein concentrations (HDL and LDL).

Analysis of the Exonic Single Nucleotide Polymorphism rs182428269 of the NRF2 Gene in Patients with Diabetic Foot Ulcer

BACKGROUND

The pivotal role of Nuclear factor erythroid-2-related factor 2 (NRF2) in redox homeostasis and wound healing has been well documented. However, the genetic mechanisms that regulate NRF2 in type 2 diabetes and diabetic foot ulcers remain unexplored. The present study investigated the association of single nucleotide polymorphism rs182428269 (-127 C/T) in subjects with type 2 diabetes and diabetic foot ulcers.

METHODS

This cross-sectional study comprised 400 participants that included group I: normal glucose tolerant subjects (NGT, n = 150), group II: type 2 diabetes mellitus subjects (T2DM, n = 150) and group III: infected diabetic foot ulcer subjects (DFU, n = 100). The non-synonymous SNP rs182428269 was selected based on in silico analysis and genotyped by PCR-restriction fragment length polymorphism (RFLP) followed by bidirectional Sanger sequencing. In addition, the gene expression of NRF2 in patients with polymorphism was analyzed by qPCR to evaluate the functional impact of the SNP.

RESULTS

NRF2 expression was significantly decreased among the T2DM and DFU subjects when compared to the NGT subjects. Of particular interest, the homozygous mutant (TT) genotype of rs182428269 polymorphism was significantly associated with an increased risk for the development of T2DM (OR = 1.95 (1.02-3.72), p = 0.04) and DFU (OR = 5.66 (2.98-10.76), p = 0.0001). Furthermore, a progressive decline in NRF2 expression was observed among the T2DM and DFU subjects with "TT" genotype compared to the "CC" and "CT" genotypes.

CONCLUSION

NRF2 polymorphism rs182428269 is associated with the pathogenesis of T2DM and DFU.

The Interactive Effect of High Doses of Chromium(III) and Different Iron(III) Levels on the Carbohydrate Status, Lipid Profile, and Selected Biochemical Parameters in Female Wistar Rats

The aim of the study was to evaluate the main and interactive effects of chromium(III) propionate complex (Cr3) supplementation and different iron supply on the carbohydrate metabolism, lipid profile and other selected biochemical parameters of rats. The experiment was carried out in a two-factor design, in which rats were fed a diet with different proportions of Fe(III) and Cr(III) for six weeks. Fifty-four healthy female Wistar rats were divided into nine experimental groups with different Fe(III) levels, i.e. adequate-control group (45 mg/kg)-100% recommended daily dietary dose of Fe for rodents, deficient (5 mg/kg) and oversupply (180 mg/kg-400%). At the same time they were supplemented with Cr(III) of doses 1 (adequate), 50 and 500 mg/kg of diet. The activity and concentrations of most biochemical parameters were measured with standard enzymatic, kinetic, and colorimetric methods. HOMA-IR and QUICKI indexes were calculated according to appropriate formulas. It was found that there was an interactive effect of high Cr(III) doses and different Fe(III) levels in the diet on the carbohydrate metabolism and insulin resistance indexes. The presented results suggested that iron deficient diet fed animals led to insulin resistance; however, an effect is attenuated by Cr(III) supplementation at high doses. There were no significant changes in the rats' lipid profile (except for the high density lipoprotein cholesterol (HDL-C) level) and most of the other biochemical parameters, such as the leptin, aspartate aminotransferase (AST), alanine transaminase (ALT), total protein (TP), creatinine (Crea) and the urea (BUN) concentrations. The study proved that the Cr(III) supplementation, independently and in combination with diversified Fe(III) content in the diet, affected the carbohydrate metabolism and insulin resistance indexes but did not affect lipid profile and most of the other biochemical parameters in healthy rats. The findings proved the role of Fe and Cr(III) and their interactions on disturbances carbohydrates metabolism.

Resolvin D1 Ameliorates Nicotinamide-streptozotocin-induced Type 2 Diabetes Mellitus by its Anti-inflammatory Action and Modulating PI3K/Akt/mTOR Pathway in the Brain

OBJECTIVE

To study whether resolvin D1 (RvD1), a metabolite of docosahexaenoic acid (DHA), prevents NA-STZ-induced type 2 diabetes mellitus (type 2 DM) in vivo and if so, what could be the mechanism of this action.

MATERIAL AND METHODS

Single intra-peritoneal (i.p) injection of NA-STZ (175 mg/kg body weight of NA and 65 mg/kg of STZ) was injected simultaneously with RvD1 (60 ng/animal) (injected for 5 consecutive days) to Wistar rats. The effect of RvD1 on plasma glucose levels and apoptotic (Bcl2/Bax) and inflammatory (NF-κB/iNOS) protein expression, plasma lipoxin A4 and BDNF (brain-derived neurotrophic factor) were studied. Protein expressions of PI3k-Akt-mTOR pathway along with histopathological studies of brain were also evaluated.

RESULTS

NA-STZ-induced type 2 DM rats showed hyperglycemia, enhanced plasma IL-6/TNF-α (p ≤0.01), reduced plasma BDNF (p ≤0.01) and LXA4 (p ≤0.01) levels and low BDNF in pancreatic, hepatic and brain tissues (p <0.001), which were restored to near normal (p ≤0.01) in RvD1 treated group. RvD1 increased insulin sensitivity by suppressing inflammation (NF-κB/iNOS) (p ≤0.01) and decreasing apoptosis (Bcl2/Bax) and restoring BDNF and LXA4 levels to near normal. RvD1 treatment increased phosphorylation of Akt (Ser473), and subsequent activation (phosphorylation) of downstream signaling molecules of PI3K and mTOR indicating that RvD1 acts through PI3K/Akt/mTOR axis.

DISCUSSION

RvD1 is effective in preventing NA-STZ-induced type 2 DM in vivo by suppressing oxidative damage, enhancing the production of anti-inflammatory LXA4 and enhancing neuronal cell survival by augmenting the production of BDNF. Thus, RvD1 may be of benefit not only in preventing diabetes mellitus but also diabetes associated Alzheimer's disease and memory loss.

Association between dietary patterns with insulin resistance in an Iranian population

AIM

To assess the association between dietary patterns no single food or group, and risk of insulin resistance (Fasting blood sugar (FBS), Fasting insulin, 2h-glucose, 2h-insulin and HOMA-IR).

METHODS

In a cross-sectional, population-based study in Tehran, Iran, 2016-2017. Adults (n = 1500, 38% men) mean age 43.72 ± 14.9 years. Dietary intake was collected by semi-quantitative food frequency questionnaire and insulin resistance was evaluated by Fasting blood sugar (FBS), Fasting insulin, 2h glucose, 2h insulin and HOMA-IR. Associations were assessed by using correlation and multivariable linear regression.

RESULTS

After controlling of the confounding factor or possible underlying such as gender, age, menopausal, BMI, physical activity and the amount of daily energy intake, unhealthy dietary pattern had a positive relationship with all indexes of insulin resistance except 2h glucose and HOMA-IR, healthy dietary pattern had negative and significant relationship with indexes of insulin resistance but apart from 2h glucose.

CONCLUSIONS

It can be figured out that receiving diet rich in healthy foods might reduce the risk of creating insulin resistance.