Distribution of HOMA-IR in a population-based cohort and proposal for reference intervals

Safflower injection against obesity-induced mice podocyte injury by improving insulin resistance through increasing renal INSR and eNOS expression

BACKGROUND

Podocyte injury is a common pathologic mechanism in obesity-related glomerulopathy (ORG). Safflower injection (SFI), scientifically extracted and refined from safflower, is used to treat diabetic kidney disease according to clinical guideline. Our previous study confirmed that the main active compounds of SFI ameliorated high glucose-induced podocyte injury. It is uncertain whether SFI has an effect on ORG-related podocyte injury.

OBJECTIVES

This study aimed to explore the pharmacological effects and related mechanisms of SFI on podocyte injury of ORG mice.

METHODS

First, by combining ultra-high performance liquid chromatography tandem mass spectrometry analysis with online databases, the pathway enrichment, target-pathway analysis, and human protein-protein interaction network were conducted to discover the possible crucial mechanism of SFI against ORG. Then, ORG mice model was established by high-fat diet and biochemical assays, histopathology and western blot were used to explore the effects of SFI on obesity and podocyte injury. Finally, system pharmacology-based findings were evaluated in ORG mice.

RESULTS

The results of system pharmacology suggested that SFI could alleviate ORG through insulin resistance (IR)-related pathway by regulating insulin receptor (INSR) and endothelial nitric oxide synthase (eNOS) expressions. The in vivo experiment confirmed that SFI ameliorated obesity, lipid metabolism-related indicators, podocyte injury of ORG mice. The mechanism relationships among IR, INSR, and eNOS were further verified in ORG mice.

CONCLUSIONS

Our findings imply that by up-regulating the expression of renal INSR and eNOS, thereby inhibiting IR, SFI may be a promising candidate for the treatment of ORG.

Frequency of insulin resistance among non-diabetic patients with non-alcoholic fatty liver disease using HOMA-IR: an experience of a tertiary care hospital in Karachi, Pakistan

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a global problem strongly interlinked with metabolic syndrome. Insulin resistance (IR) is a key factor both in pathogenesis and in the progression to liver fibrosis. This article highlights the frequency of IR in local population.

OBJECTIVE

To determine the frequency and associated factors of insulin resistance among non-diabetic patients with NAFLD using HOMA-IR.

MATERIALS AND METHODS

A prospective cross-sectional study was conducted at Liaquat National Hospital, Karachi. 362 non-diabetic patients diagnosed with NAFLD were divided into two groups: with IR and without IR. Clinical history, physical examination, laboratory tests (fasting lipid profile, fasting glucose, insulin, liver function tests) and abdominal ultrasound with fibroscan for liver steatosis assessment were performed. Controlled Attenuation Parameter (CAP) score of ≥ 238 dB/m was used to define hepatic steatosis and metabolic syndrome was diagnosed based on specific clinical and laboratory criteria. Data was analyzed using SPSS version 27.

RESULTS

Total 362 patients were enrolled and 51.7% were male patients. 311(85.9%) participants had insulin resistance. Insulin resistance had significant difference for HDL, LDL, FPG, Fasting plasma insulin, and GGT. Male patients are less likely than female patients to exhibit insulin resistance. Insulin resistance is more common in patients with metabolic syndrome than in non-metabolic patients.

CONCLUSION

Among non-diabetic patients with NAFLD, insulin resistance was highly prevalent and majority of patients were obese. Both genders were affected with IR.

More comprehensive relationship between eGDR and sarcopenia in China: a nationwide cohort study with national representation

INTRODUCTION

Although studies had shown that Insulin resistance (IR) was correlated with the occurrence of sarcopenia, there were still many controversial conclusions. Therefore, we conducted a more comprehensive study on the relationship between the estimated glucose disposal rate (eGDR), an alternative indicator of IR, and the risk of sarcopenia, muscle mass, and muscle strength to clarify their interactions.

METHODS

The Study included individuals from The China Health and Retirement Longitudinal Study (CHARLS) who had complete eGDR data at baseline and did not develop low muscle mass and low muscle strength. The individuals were divided into four subgroups based on the quartile (Q) of the eGDR. The lowest quartile (Q1) of the eGDR was used as a reference. Logistic regression and linear regression were used to evaluate the relationship between eGDR and sarcopenia (low muscle mass, low muscle strength, possible sarcopenia, and sarcopenia) and sarcopenia related features (ASM/Ht2, grip, and RMS), respectively. In addition, we further evaluated the nonlinear relationship using smooth curve fitting and threshold effect analysis.

RESULTS

The results showed that after adjusting for confounders, eGDR was negatively associated with the risk of sarcopenia and positively associated with sarcopenia related characteristics. In addition, men showed a more significant reduction in the likelihood of low muscle mass compared to women. But as eGDR levels rise, women gain more ASM/Ht2. Further nonlinear analysis revealed an inverse correlation between eGDR and ASM/Ht2 at the inflection point of 15.3893. Besides that, eGDR was positively correlated with grip (7.1862) and RMS (11.1042) before the inflection point.

CONCLUSIONS

The study found that higher levels of eGDR were associated with a lower risk of developing sarcopenia. However, the effects of eGDR on muscle mass and muscle strength need to be considered comprehensively. For muscle mass, it is recommended to maintain eGDR below 15.3893, and for muscle strength, it is recommended to maintain eGDR below 7.1862, with more potential benefits for early warning of sarcopenia.

Insulin Resistance in Hypercalciuric Calcium Kidney Stone Patients

Rational & Objective

Diabetes and uric acid kidney stones are strongly associated. Patients with calcium kidney stones also have higher risk of developing diabetes compared with nonkidney stone patients yet this has not been further investigated. We aimed to characterize insulin resistance in calcium kidney stone patients.

Study Design

Observational.

Setting & Population

This study was performed in the University of Chicago Clinical Research Center. Kidney stone patients (N = 42) were selected for having idiopathic hypercalciuria and calcium stones with no other medical conditions, and controls (N = 27) were healthy.

Exposures

All participants presented to the Clinical Research Center in a fasting state and at least 2 timed fasting blood and urine collections were collected before a fixed breakfast. Six additional timed blood and urine collections were performed after breakfast.

Outcomes

We compared fasting and fed indices of insulin resistance between the groups.

Analytic Approach

We used t tests and multivariable linear regression models. A sensitivity analysis removing all patients who had ever been on a thiazide diuretic was also performed.

Results

In separate multivariable linear models, kidney stone patients had higher fasting serum insulin levels (24 (3-46 pmol/L), P = 0.03) and higher homeostatic model of insulin resistance (HOMA-IR) (1.0 (0.2-1.8), P = 0.02). In separate multivariable linear models, kidney stone patients had higher fed serum glucose levels (10 (2-18 mg/dL), P = 0.01). Results were similar in a sensitivity analysis removing all patients who had ever been on a thiazide diuretic. There were no differences in urine composition based on HOMA-IR levels.

Limitations

Single institution. Small sample size limited subanalyses by different calcium stone types.

Conclusions

Calcium kidney stone patients without diabetes or other medical conditions demonstrated signs of insulin resistance compared with healthy matched controls.

Proposal for fasting insulin and HOMA-IR reference intervals based on an extensive Brazilian laboratory database

Objective

Fasting insulin and the homeostasis model assessment of insulin resistance (HOMA-IR) index are relatively simple and reliable noninvasive markers of insulin resistance (IR). Given the relevance of correctly diagnosing IR, we emphasize the importance of establishing reliable reference intervals (RIs) for these markers. This study aimed to determine the RIs of fasting insulin and HOMA-IR index in adults living in Rio de Janeiro and, secondarily, to verify potential RI differences between sexes.

Subjects and methods

Serum insulin levels of 146,497 individuals (ages 20-60 years) who underwent blood sampling in the state of Rio de Janeiro were obtained retrospectively through access to an extensive laboratory database. Insulin was measured using the electrochemiluminescence immunoassay method. After applying exclusion criteria, 21,684 individuals (18,576 [86%] women) were included. The RIs were estimated using a computational mining approach that integrates a selection of R packages.

Results

The 95% RIs in women and men and in the overall population were, respectively, 2.54-13.30 μU/mL (15.3-80.12 pmol/L), 2.43-11.89 μU/mL (14.6-71.7 pmol/L), and 2.52-13.14 μU/mL (15.2-79.2 pmol/L) for fasting insulin levels and 0.39-2.86, 0.38-2.81, and 0.39-2.86 for HOMA-IR values. Despite significant differences in insulin levels and HOMA-IR index between men and women, the use of sex-specific RIs was not justified.

Conclusion

The RIs of fasting insulin levels and HOMA-IR values found in the overall population can be applied to both sexes. Thus, for our population, we suggest the RIs of 2.52-13.14 μU/mL (15.1-78.8 pmol/L) for fasting insulin and 0.39-2.86 for the HOMA-IR index.

Exploring Gender Differences in the Association Between TyG Index and COPD: A Cross-Sectional Study from NHANES 1999-2018

Purpose

This study examined gender differences in the association of Triglyceride-Glucose (TyG) index with the prevalence of chronic obstructive pulmonary disease (COPD), particularly in a non-diabetic population.

Methods

The study leveraged data from the National Health and Nutrition Examination Survey (NHANES), spanning from 1999 to 2018, with a cohort of 23,456 participants. Logistic regression and restricted cubic spline analyses were employed to explore the relationship between the TyG index and COPD prevalence.

Results

Statistical analyses revealed a significant positive association between the TyG index and COPD prevalence among non-diabetic women after adjustment for all covariates (OR=1.50; 95% CI, 1.08-2.08), supported by a linear relationship (P for non-linearity=0.298). No equivalent significant association was found in non-diabetic men (OR=1.00; 95% CI, 0.67-1.48). Within the diabetic group, the TyG index did not show a significant association with COPD prevalence, regardless of gender.

Conclusion

Our study reveals a significant positive correlation between the TyG index and COPD prevalence in the non-diabetic population, marked by notable gender differences.

Predictors of Kidney Function Outcomes and Their Relation to SGLT2 Inhibitor Dapagliflozin in Patients with Type 2 Diabetes Mellitus Who Had Chronic Heart Failure

INTRODUCTION

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have a favorable impact on the kidney function in patients with heart failure (HF), while there is no clear evidence of what factors predict this effect. The aim of the study was to identify plausible predictors for kidney function outcome among patients with HF and investigate their association with SGLT2i.

METHODS

We prospectively enrolled 480 patients with type 2 diabetes mellitus (T2DM) treated with diet and metformin and concomitant chronic HF and followed them for 52 weeks. In the study, we determined kidney outcome as a composite of ≥ 40% reduced estimated glomerular filtration rate from baseline, newly diagnosed end-stage kidney disease or kidney replacement therapy. The relevant medical information and measurement of the biomarkers (N-terminal natriuretic pro-peptide, irisin, apelin, adropin, C-reactive protein, tumor necrosis factor-alpha) were collected at baseline and at the end of the study.

RESULTS

The composite kidney outcome was detected in 88 (18.3%) patients of the entire population. All patients received guideline-recommended optimal therapy, which was adjusted to phenotype/severity of HF, cardiovascular risk and comorbidity profiles, and fasting glycemia. Levels of irisin, adropin and apelin significantly increased in patients without clinical endpoint, whereas in those with composite endpoint the biomarker levels exhibited a decrease with borderline statistical significance (p = 0.05). We noticed that irisin ≤ 4.50 ng/ml at baseline and a ≤ 15% increase in irisin serum levels added more valuable predictive information than the reference variable. However, the combination of irisin ≤ 4.50 ng/ml at baseline and ≤ 15% increase in irisin serum levels (area under curve = 0.91; 95% confidence interval = 0.87-0.95) improved the discriminative value of each biomarker alone.

CONCLUSION

We suggest that low levels of irisin and its inadequate increase during administration of SGLT2i are promising predictors for unfavorable kidney outcome among patients with T2DM and concomitant HF.

Genome-wide analysis study of gestational diabetes mellitus and related pathogenic factors in a Chinese Han population

BACKGROUND

Gestational diabetes mellitus (GDM) affects the metabolism of both the mother and fetus during and after pregnancy. Genetic factors are important in the pathogenesis of GDM, and associations vary by ethnicity. However, related studies about the relationship between the susceptibility genes and glucose traits remain limited in China. This study aimed to identify genes associated with GDM susceptibility in Chinese Han women and validate those findings using clinical data during pregnancy and postpartum period.

METHODS

A genome-wide association study (GWAS) of 398 Chinese Han women (199 each with and without GDM) was conducted and associations between single nucleotide polymorphisms (SNPs) and glucose metabolism were identified by searching public databases. Relationships between filtered differential SNPs and glucose metabolism were verified using clinical data during pregnancy. The GDM group were followed up postpartum to evaluate the progression of glucose metabolism.

RESULTS

We identified five novel SNPs with genome-wide significant associations with GDM: rs62069863 in TRPV3 gene and rs2232016 in PRMT6 gene were positive correlated with 1 h plasma glucose (1hPG) and 2 h plasma glucose (2hPG), rs1112718 in HHEX/EXOC6 gene and rs10460009 in LPIN2 gene were positive associated with fasting plasma glucose, 1hPG and 2hPG, rs927316 in GLIS3 gene was negative correlated with 2hPG. Of the 166 GDM women followed up postpartum, rs62069863 in TRPV3 gene was positively associated with fasting insulin, homoeostasis model assessment of insulin resistance.

CONCLUSIONS

The variants of rs62069863 in TRPV3 gene, rs2232016 in PRMT6 gene, rs1112718 in HHEX/EXOC6 gene, rs927316 in GLIS3 gene, and rs10460009 in LPIN2 gene were newly-identified susceptibility loci for GDM in the Chinese Han population. TRPV3 was associated with worse insulin resistance postpartum.

TRIAL REGISTRATION

This study was registered in the Chinese Clinical Trial Registry.

TRIAL REGISTRATION NUMBER

ChiCTR2100043762. Date of first registration: 28/02/2021.

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.

HOMA-IR is an effective biomarker of non-alcoholic fatty liver disease in non-diabetic population

OBJECTIVES

This study aimed to investigate the correlation between homeostasis model assessment of insulin resistance (HOMA-IR) and non-alcoholic fatty liver disease (NAFLD) in the non-diabetic population and establish its diagnostic efficacy.

METHODS

This observational study involved participants divided into NAFLD and non-NAFLD groups, and baseline data were analyzed. Univariate and multivariate logistic regression analyses were used to correlate HOMA-IR with the risk of NAFLD. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic efficacy of HOMA-IR for NAFLD. Subgroup analyses of non-obese individuals were performed.

RESULTS

Overall, 2234 non-diabetic participants were included. The HOMA-IR was significantly higher in the NAFLD group than in the non-NAFLD group. Multivariate logistic regression analysis showed that HOMA-IR was a strong and independent risk factor for NAFLD after correcting for confounding factors. The area under the ROC curve (AUC) value of HOMA-IR for predicting NAFLD was 0.792. In the non-obese non-diabetic population, HOMA-IR was an independent risk factor for increased risk of lean NAFLD after correcting for confounding factors. The AUC value of HOMA-IR for predicting lean NAFLD was 0.770.

CONCLUSIONS

HOMA-IR is independently associated with the risk of NAFLD in the non-diabetic and non-obese non-diabetic populations and has good diagnostic value.

Trends in HOMA-IR values among South Korean adolescents from 2007-2010 to 2019-2020: a sex-, age-, and weight status-specific analysis

BACKGROUND/OBJECTIVES

An increase in obesity prevalence may lead to an increase in the HOMA-IR value. This study aimed to investigate changes in age- and sex-specific homeostasis model assessment of insulin resistance (HOMA-IR) values among South Korean adolescents, using data from the Korean National Health and Nutrition Examination Survey (KNHANES) IV, V, and VIII conducted between 2007-2010 and 2019-2020.

SUBJECTS/METHODS

Overall, 4621 adolescents aged 10-18 years were evaluated, including 3473 from the 2007-2010 dataset and 1148 from the 2019-2020 dataset. The mean HOMA-IR values and percentile curves were evaluated by age, sex, and weight status.

RESULTS

The mean HOMA-IR values peaked at puberty in both sexes and further increased during puberty in the 2019-2020 dataset (boys 5.21, 95% confidence interval [CI] 4.16-6.26; girls 5.21, 95% CI 3.09-7.33) compared with the 2007-2010 dataset (boys 3.25, 95% CI 3.04-3.47; girls 3.58, 95% CI 3.31-3.85). Both groups (with normal-weight and overweight/obesity) exhibited a peak HOMA-IR value during puberty in both sexes and both datasets, although the group with overweight/obesity had a higher and wider peak age range. While the mean HOMA-IR values did not change in adolescents with normal-weight, they increased during puberty and post-puberty in boys with overweight/obesity.

CONCLUSIONS

HOMA-IR values should be interpreted considering sex, weight status, and pubertal stages. In particular, during the pubertal period, insulin resistance (IR) can coexist not only due to weight-related factors but also as a result of the distinct hormonal changes characteristic of puberty. Over the 10-year period, the mean HOMA-IR values increased in the group with overweight/obesity during puberty and post-puberty, highlighting the need for active intervention to prevent metabolic complications in adolescents with overweight/obesity.

Plant-Based Nutrition: Exploring Health Benefits for Atherosclerosis, Chronic Diseases, and Metabolic Syndrome-A Comprehensive Review

Atherosclerosis, chronic non-communicable diseases, and metabolic syndrome are highly interconnected and collectively contribute to global health concerns that reduce life expectancy and quality of life. These conditions arise from multiple risk factors, including inflammation, insulin resistance, impaired blood lipid profile, endothelial dysfunction, and increased cardiovascular risk. Adopting a plant-based diet has gained popularity as a viable alternative to promote health and mitigate the incidence of, and risk factors associated with, these three health conditions. Understanding the potential benefits of a plant-based diet for human health is crucial, particularly in the face of the rising prevalence of chronic diseases like diabetes, hypertension, dyslipidemia, atherosclerosis, and cancer. Thus, this review focused on the plausible advantages of consuming a type of food pattern for the prevention and/or treatment of chronic diseases, emphasizing the dietary aspects that contribute to these conditions and the evidence supporting the benefits of a plant-based diet for human health. To facilitate a more in-depth analysis, we present separate evidence for each of these three concepts, acknowledging their intrinsic connection while providing a specific focus on each one. This review underscores the potential of a plant-based diet to target the underlying causes of these chronic diseases and enhance health outcomes for individuals and populations.

Can orbital artery resistive indexes detect complications of diabetes in the prediabetic phase?

AIM

Prediabetic patients have generalized microvascular dysfunction, which leads to end-organ damage, just like diabetes. Therefore, prediabetes is not just a mild elevation in blood sugar, and early detection and prevention of possible complications should be the main goal. Color Doppler imaging (CDI) provides morphologic and vascular information on various diseases. The Resistive Index (RI) is a widely used measure of resistance to arterial flow and is calculated from the CDI. CDI evaluation of vessels in the retrobulbar region may be the first sign of micro- and macrovascular complications.

METHOD

Consecutively, 55 prediabetic patients and 33 healthy subjects were recruited for the study. Prediabetic patients were divided into three groups according to their fasting and postprandial blood glucose values. The groups included an impaired fasting glucose (IFG) group (n = 15), an impaired glucose tolerance (IGT) group (n = 13), and an IFG+IGT group (n = 27). The RI of the ophthalmic artery, posterior ciliary artery, and central retinal artery were measured in all patients.

RESULTS

The orbital artery, central retinal artery, and posterior cerebral artery mean RI of prediabetic patients (0.76 ± 0.06, 0.69 ± 0.03, and 0.69 ± 0.04, respectively) were significantly higher than those of the healthy group (0.66 ± 0.04, 0.63 ± 0.04, and 0.66 ± 0.04, respectively; p < 0.001; Student's t-test). The mean ophthalmic artery RI of the healthy, IFG, IGT, and IFG+IGT groups were 0.66 ± 0.39, 0.7 ± 0.27, 0.72 ± 0.29, and 0.82 ± 0.16, respectively, with a significant difference between the groups (p < 0.001, ANOVA). The mean central retinal artery RI of the healthy, IFG, IGT, and IFG+IGT groups were 0.63 ± 0.04, 0.66 ± 0.02, 0.7 ± 0.02, and 0.71 ± 0.02, respectively (p < 0.001, post-hoc Tukey). The mean posterior cerebral artery RI of the healthy, IFG, IGT, and IFG+IGT groups were 0.66 ± 0.04, 0.66 ± 0.04, 0.69 ± 0.03, and 0.71 ± 0.03, respectively, with a significant difference between the groups (p < 0.001 Fisher ANOVA).

CONCLUSION

Increased RI may be the first sign of developing retinopathy, as well as the first sign of microangiopathies occurring simultaneously in the coronary, cerebral, and renal vessels. Precautions to be taken during the prediabetic stage can prevent many possible complications.

Severe Dyslipidemia Mimicking Familial Hypercholesterolemia Induced by High-Fat, Low-Carbohydrate Diets: A Critical Review

Emerging studies in the literature describe an association between high-fat, low-carbohydrate diets and severe hypercholesterolemia consistent with the levels observed in patients with (homozygous) familial hypercholesterolemia (FH). High levels of low-density lipoprotein cholesterol (LDL-C) may result from the reduced clearance of LDL particles from the circulation, the increased production of their precursor, or a combination of both. The increased intake of (saturated) fat and cholesterol, combined with limited to no intake of carbohydrates and fiber, are the main features of diets linked to hypercholesterolemia. However, several observations in previous studies, together with our observations from our lipid clinic, do not provide a definitive pathophysiological explanation for severe hypercholesterolemia. Therefore, we review these findings and possible pathophysiological explanations as well as opportunities for future research. Altogether, clinicians should rule out high-fat, low-carbohydrate diets as a possible cause for hypercholesterolemia in patients presenting with clinical FH in whom no mutation is found and discuss dietary modifications to durably reduce LDL-C levels and cardiovascular disease risk.

The homeostasis model assessment of insulin resistance is a judgment criterion for metformin pre-treatment before IVF/ICSI and embryo transfer cycles in patients with polycystic ovarian syndrome

PURPOSE

The aim of this study was to explore the value of the homeostasis model assessment of IR (HOMA-IR) as a judgment criterion for metformin pre-treatment before in vitro fertilization/intracellular sperm injection (IVF/ICSI) and embryo transfer (ET) for polycystic ovarian syndrome (PCOS) patients.

MATERIALS AND METHODS

The clinical and laboratory information of PCOS patients who received IVF/ICSI-ET from January 2017 to September 2021 was retrospectively analyzed. We compared the clinical pregnancy rate (primary outcome) and controlled ovarian stimulation (COS)-related parameters (secondary outcomes) between patients with and without metformin pre-treatment for all PCOS patients not grouped by HOMA-IR, PCOS patients with HOMA-IR < 2.71, and PCOS patients with HOMA-IR ≥ 2.71.

RESULTS

A total of 969 PCOS patients who received the GnRH-antagonist protocol were included in this study. For all PCOS patients, the metformin group showed comparable clinical pregnancy rates in fresh ET cycles and frozen ET cycles compared with the control group (55.9% vs. 57.1%, p = 0.821 and 63.8% vs. 60.9%, p = 0.497). For PCOS patients with HOMA-IR < 2.71, the clinical pregnancy rates in both fresh ET cycles and frozen ET cycles were statistically similar between the two groups (61.5% vs. 57.6%, p = 0.658 and 70.6% vs. 66.7%, p = 0.535). For PCOS patients with HOMA-IR ≥ 2.71, the clinical pregnancy rate in fresh ET cycles was comparable between the two groups (51.5% vs. 56.3, p = 0.590), but it was statistically higher in the metformin group than in the control group in frozen ET cycles (57.1% vs. 40.0%, p = 0.023). The metformin group had less oocytes retrieved, a lower cleaved oocyte rate, a lower available D3 embryo rate, a lower blastocyst formation rate, and a lower available blastocyst rate than the control group.

CONCLUSION

HOMA-IR is a judgment criterion for metformin pre-treatment before IVF/ICSI-ET in patients with PCOS. Metformin pre-treatment could be added for PCOS patients with HOMA-IR ≥ 2.71 during frozen IVF/ICSI-ET cycles to improve the clinical pregnancy rate.

Associations of Serum Total 25OHD, 25OHD3, and epi-25OHD3 with Insulin Resistance: Cross-Sectional Analysis of the National Health and Nutrition Examination Survey, 2011–2016

Background: Vitamin D may have a role in insulin sensitivity. However, the data on the association between various metabolites of Vitamin D and insulin-related parameters have been limited. Methods: We identified 6026 adults aged 20–80 years who participated in the 2011–2016 National Health and Nutrition Examination Survey (NHANES). Serum total 25OHD, 25OHD3, and epi-25OHD3, fasting glucose, insulin, and HOMA2-IR were obtained from the NHANES data. The association between serum Vitamin D-related values and insulin resistance was analyzed using a generalized linear model. For risk analysis, multifactorial logistic regression was used. Results: The median total 25-hydroxyvitamin D level, 25-hydroxyvitamin D3 level, and 3-epi-25-hydroxyvitamin D3 level were 62.5 nmol/L, 58.8 nmol/L, and 3.3 nmol/L, respectively. After adjustment for sex, age, race, ethnicity, and education status, the ORs for the insulin resistance of participants of total 25-hydroxyvitamin D, 25-hydroxyvitamin D3, and 3-epi-25-hydroxyvitamin D3 were 0.32 (95% CI 0.24, 0.43), 0.34 (95% CI 0.26, 0.44), and 0.64 (95% CI 0.53, 0.77), respectively. After an adjustment for body mass index, diabetes, and drinking and smoking, the ORs for the insulin resistance of the participants for total 25-hydroxyvitamin D, 25-hydroxyvitamin D3, and 3-epi-25-hydroxyvitamin D3 were 0.56 (95% CI 0.40, 0.78), 0.63 (95% CI 0.46, 0.85), and 0.99 (95% CI 0.80, 1.24), respectively. Conclusions: Our study provides suggestive evidence for the association between Vitamin D concentrations and a lower risk of insulin resistance. Evidence from larger and more adequately powered cohort studies is needed to confirm our results.

Dose-Response Associations of Metabolic Score for Insulin Resistance Index with Nonalcoholic Fatty Liver Disease among a Nonobese Chinese Population: Retrospective Evidence from a Population-Based Cohort Study

Purpose

This study is aimed at investigating the association between the metabolic score for insulin resistance (METS-IR) index and nonalcoholic fatty liver disease (NAFLD) in the nonobese population and its predictive value.

Methods

10730 nonobese subjects were selected from longitudinal cohort research conducted from January 2010 to December 2014. Cox proportional hazards models were employed to assess the relationship between METS-IR and new-onset NAFLD. Generalized additive models were used to identify nonlinear relationships. In addition, we performed subgroup analyses and interaction tests. The time-dependent receiver operating curve (ROC) and area under the ROC (AUC) were utilized to measure the discriminatory ability of METS-IR for new-onset NAFLD. Beyond clinical risk factors, the incremental predictive value of METS-IR was appraised using integrated discrimination improvement (IDI), C-index, and net reclassification index (NRI).

Results

Over a median period of 804.50 days of follow-up, 1859 (17.33%) participants had a new onset of NAFLD. After adjusting for confounders, the HR for new-onset NAFLD in the Q4 group was 6.40 compared with the Q1 group. When METS-IR was considered a continuous variable, the risk of NAFLD increased by 34% for every 1 SD increase in METS-IR. The smoothing curve shows the dose-response relationship between METS-IR and the presence of new-onset NAFLD. Using a two-piecewise linear regression model, we derived a METS-IR inflection point of 36. HRs were 1.31 on the left side of the inflection point and 1.04 on the right side of the inflection point (log-likelihood ratio test, P < 0.001). Subgroup analyses and interaction tests revealed an interaction between gender and SBP in the association between METS-IR and new-onset NAFLD. In the subgroup analysis of gender and SBP, we observed a higher risk of new-onset NAFLD in men and in those with abnormal SBP levels. We evaluated the ability of METS-IR to identify new-onset NAFLD at different time points. The AUCs at 1, 2, 3, and 4 years were 0.784, 0.756, 0.758, and 0.752, respectively, which represent good discrimination of new-onset NAFLD. The addition of METS-IR greatly improved the reclassification and differentiation of clinical risk factors, with an NRI of 0.276 and an IDI of 0.068. In addition, the addition of METS-IR increased the C-index from 0.719 to 0.771.

Conclusion

In a nonobese Chinese population, elevated METS-IR was independently associated with an enhanced risk of NAFLD development and a dose-response relationship existed. In addition, METS-IR might be a reliable indicator for screening individuals at risk for early NAFLD, especially in nonobese populations.