Insulin Resistance and Risk of Cardiovascular Disease in Postmenopausal Women

Combined influence of depression symptoms and ratio of triglyceride to high-density lipoprotein cholesterol on cardiometabolic multimorbidity: Findings from the China Health and Retirement Longitudinal Study 2011-2018

BACKGROUND

Previous studies had reported depression symptoms and TG/HDLC ratio may share pathophysiological pathway. The aim was to investigate the combined effects of depression symptoms and TG/HDL-C ratio on the risk of CMM.

METHODS

This cohort study extracted data from 2011 to 2018 of CHARLS. The CMM event occurred from 2013 to 2018, defined as suffering from more than one of stroke, cardiac events, and diabetes mellitus. Cox proportional hazards regression models were used to assess the association between the baseline combined effects of depression symptoms and TG/HDL-C ratio with incidence of CMM, stroke, cardiac events, and diabetes mellitus.

RESULTS

A total of 8349 participants (3966 men and 4383 women) were included in the study, with a mean age of 58.5 years. During a 7-year follow-up survey, 370 (4.43 %) participants developed CMM. Compared to individuals with no depression symptoms and low TG/HDLC ratio, the multivariable-adjusted HRs (95%CI) for the new-onset CMM for patients with the depression symptoms alone, high TG/HDLC ratio alone, and depression symptoms and high TG/HDLC ratio were 1.37 (95 % CI = 0.95-1.98), 1.62 (95 % CI = 1.22-2.14), 1.94 (95 % CI = 1.39-2.72), respectively (P < 0.001).

LIMITATIONS

Firstly, potential confounding factors such as dietary intake and nutrition were not collected at the time of study design. Secondly, exposure to the outcome was self-reported, which may cause recall bias or misclassification. Finally, the population was aged ≥45 years, so the results cannot be generalized to all age groups.

CONCLUSION

Our findings indicated that patients with depression and high TG/HDLC ratio had a higher risk of developing CMM.

Estimated glucose disposal rate and risk of cardiovascular disease and mortality in U.S. adults with prediabetes: a nationwide cross-sectional and prospective cohort study

AIMS

Estimated glucose disposal rate (eGDR), a noninvasive and convenient measure of insulin resistance, has been demonstrated to be associated with mortality in both type 1 and type 2 diabetes. We aimed to explore whether eGDR is associated with cardiovascular disease (CVD) risk and mortality in prediabetic adults.

METHODS

A nationwide population-based cohort of prediabetic individuals from the National Health and Nutrition Examination Survey 1999-2018 with available data on eGDR was included and categorized into eGDR ≥ 8 (reference), 6-7.99, 4-5.99, and < 4 mg/kg/min groups. Cox proportional hazards model was used to estimate the associations of eGDR with mortality.

RESULTS

A total of 4725 prediabetic adults, 60.12% men, mean age 48 years were included. The odds ratio and 95% confidence interval (CI) for CVD risk were 1.74 (1.08-2.78), 2.90 (1.79-4.67), and 4.58 (2.15-9.76) for the eGDR 6-7.99, 4-5.99, and < 4 mg/kg/min groups, respectively, compared with the reference group. There were 410 deaths (116 CVD-related) during a median follow-up of 107 months in 4,332 participants without baseline CVD. The hazard ratios and 95%CI for the eGDR 6-7.99, 4-5.99, and < 4 mg/kg/min groups were 1.70 (1.23-2.35), 2.01 (1.45-2.77), and 1.84 (1.11-3.04), respectively, for all-cause mortality (P for trend < 0.0001), and 3.84 (2.04-7.21), 4.01 (2.01-8.00), and 2.88 (1.03-8.06), respectively, for CVD mortality (P for trend = 0.01). Smoking status significantly modified the associations between eGDR and all-cause or CVD mortality.

CONCLUSIONS

Increased insulin resistance, as indicated by a lower eGDR, is associated with increased risks of all-cause and CVD mortality in U.S. prediabetic adults.

Joint association of TyG index and high sensitivity C-reactive protein with cardiovascular disease: a national cohort study

BACKGROUND

Both the triglyceride-glucose (TyG) index, as a surrogate marker of insulin resistance, and systemic inflammation are predictors of cardiovascular diseases; however, little is known about the coexposures and relative contributions of TyG index and inflammation to cardiovascular diseases. Using the nationally representative data from the China Health and Retirement Longitudinal Study (CHARLS), we conducted longitudinal analyses to evaluate the joint and mutual associations of the TyG index and high-sensitivity C-reactive protein (hsCRP) with cardiovascular events in middle-aged and older Chinese population.

METHODS

This study comprised 8 658 participants aged at least 45 years from the CHARLS 2011 who are free of cardiovascular diseases at baseline. The TyG index was calculated as Ln [fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2]. Cardiovascular events were defined as the presence of physician-diagnosed heart disease and/or stroke followed until 2018.We performed adjusted Cox proportional hazards regression and mediation analyses.

RESULTS

The mean age of the participants was 58.6 ± 9.0 years, and 3988 (46.1%) were females. During a maximum follow-up of 7.0 years, 2606 (30.1%) people developed cardiovascular diseases, including 2012 (23.2%) cases of heart diseases and 848 (9.8%) cases of stroke. Compared with people with a lower TyG index (< 8.6 [median level]) and hsCRP < 1 mg/L, those concurrently with a higher TyG and hsCRP had the highest risk of overall cardiovascular disease (adjusted hazard ratio [aHR], 1.300; 95% CI 1.155-1.462), coronary heart disease (aHR, 1.294; 95% CI 1.130-1.481) and stroke (aHR, 1.333; 95% CI 1.093-1.628), which were predominant among those aged 70 years or below. High hsCRP significantly mediated 13.4% of the association between the TyG index and cardiovascular disease, while TyG simultaneously mediated 7.9% of the association between hsCRP and cardiovascular risk.

CONCLUSIONS

The findings highlight the coexposure effects and mutual mediation between the TyG index and hsCRP on cardiovascular diseases. Joint assessments of the TyG index and hsCRP should be underlined for the residual risk stratification and primary prevention of cardiovascular diseases, especially for middle-aged adults.

Association between triglyceride glucose index and depression in hypertensive population

Growing evidence suggests that hypertensive individuals have a greater risk of developing depression, and depression can also increase the incidence of hypertension. In the hypertensive population, the association between triglyceride glucose (TyG) index and depression remains unclear. This study aimed to assess the association between TyG index and depression in hypertensive people through the cross-sectional study of the National Health and Nutrition Examination Survey (2007-2018). To assess the relationship between TyG index and depression in hypertensive population, we conducted weighted multiple logistic regression models and used a generalized additive model to probe for nonlinear correlations. In addition, we employed a recursive algorithm to determine the inflection point and established a two-piece linear regression model. This study enrolled 5897 individuals. In the model adjusted for all covariates, the ORs (95% CI) for the relationship between TyG index and depression in hypertensive population were 1.32 (1.12-1.54). A nonlinear association was found between TyG index and depression, with an inflection point at 8.7. After the inflection point, the ORs (95% CI) were 1.44 (1.15-1.79). Only the interaction with the obese population was statistically significant. Our study highlighted a nonlinear association between TyG index and depression in American hypertensive adults.

Association between triglyceride-glucose index and risk of cardiovascular disease among postmenopausal women

OBJECTIVE

We aimed to examine the association of triglyceride-glucose index (TyG) with risk for cardiovascular disease (CVD) among postmenopausal women.

METHODS

A total of 7741 participants met the inclusion criteria, and were included in the analysis. The TyG index was calculated as ln (triglyceride [mg/dL] × fasting blood glucose [mg/dL]/2). The participants were classified into four groups by the quartiles of TyG index, and the Q1 group was used as the reference group. The cumulative incidence of CVD for the groups were compared using the Kaplan-Meier curves. The association between the TyG index and risk of CVD among postmenopausal women was assessed by the Cox proportional hazards models (hazard ratio [HR], 95% confidence intervals [CI]).

RESULTS

During a median follow-up of 12 years, a total of 383 (4.95%) participants developed incident CVD. After adjusting for potential confounding factors, a high baseline TyG index (Q4 group) was associated with higher future risk of CVD, the HR (95% CI) of CVD risk was 1.70 (1.21-2.38) in Q4 group compared with the Q1 group. Subgroup analyses showed the Q4 group was significantly associated with the risk of CVD, regardless of age at menopause (younger than 50 years; 50 years and older) and obesity status.

CONCLUSIONS

Higher TyG index at baseline as a marker of insulin resistance (IR), is associated with higher risk of future CVD among postmenopausal women. The TyG index may serve as a simple and easy marker for early identification of high-risk individuals in the postmenopausal women.

The triglycerides-glucose index and the triglycerides to high-density lipoprotein cholesterol ratio are both effective predictors of in-hospital death in non-diabetic patients with AMI

Background

The triglycerides-glucose index (TyG) and the triglycerides to high-density lipoprotein cholesterol (TG/HDL-C) are simple indicators for assessing insulin resistance in epidemiological studies. We aimed to clarify the relationship between indicators of insulin resistance and prognosis in non-diabetic acute myocardial infarction (AMI) patients.

Methods

A total of 1,648 AMI patients without diabetes were enrolled from the Department of Cardiology, Zhongda Hospital, between 2012.03 and 2018.12. The medical history, laboratory and imaging data of patients were collected through the medical record system, and all-cause death events were recorded. Pearson analysis was used to study the correlation among different variables. Logistic regression analysis was used to analyze the predictive effect of TyG and TG/HDL-C in in-hospital death of AMI patients.

Results

1. In AMI group, the TyG index was significantly increased in death groups compared to no-death groups (P = 0.025). TG/HDL-C was not significantly increased in the death group of AMI patients (P = 0.588). The patients were respectively divided into Q1-Q4 groups and T1-T4 groups according to the quartiles of TyG and TG/HDL-C. The trends of in-hospital mortality in the Q4 group of TyG and T4 group of TG/HDL-C were higher than in other groups, although these differences were not significant. 2. Pearson correlation analysis showed that TyG was positively correlated with lipid-related markers, including ApoB (r = 0.248, P < 0.001), total cholesterol (TC) (r = 0.270, P < 0.001), low-density lipoprotein cholesterol (LDL-C) (r = 0.238, P < 0.001). Spearman analysis showed that TG/HDL-C was also positively associated with TC (r = 0.107, P < 0.001), ApoB (r = 0.180, P < 0.001) and LDL-C (r = 0.164, P < 0.001). 3. Logistic regression analysis showed that TyG (OR = 3.106, 95% CI [2.122-4.547], P < 0.001) and TG/HDL-C (OR = 1.167, 95% CI [1.062-1.282], P = 0.001) were both important factors to predict the in-hospital death of AMI patients without diabetes.

Conclusions

TyG index and TG/HDL-C, as emerged simple markers of insulin resistance, were both important predictors of in-hospital death in AMI patients without diabetes.

Effects of a yoga-based stress reduction intervention on stress, psychological outcomes and cardiometabolic biomarkers in cancer caregivers: A randomized controlled trial

Caregiving stress is a risk factor for cardiometabolic disease. Therefore, integrating cardiometabolic biomarkers into caregiving research provides a more comprehensive assessment of an individual’s health and response to an intervention. The objective of this study was to examine the effects of a yoga-based stress reduction intervention on stress, psychological outcomes, and cardiometabolic biomarkers in cancer caregivers. This prospective randomized controlled trial enrolled family caregivers of adult patients who underwent an allogeneic HSCT at the National Institutes of Health (NIH) Clinical Center. All subjects received usual care education. Participants in the intervention group received an Iyengar yoga intervention self-administered over six weeks using an audio recording file. The primary outcome was perceived stress (measured using the NIH toolbox Perceived Stress). The secondary outcomes were psychological factors (depression and anxiety measured using PROMIS® Depression and Anxiety), and cardiometabolic biomarkers measured by nuclear magnetic resonance spectroscopy. A total of 50 family caregivers (mean [SD] age, 44.9 [15.2] years; 42 [84.0%] women) were randomized, 25 to the intervention group and 25 to the control group. No group differences were noted in stress, depression, and anxiety. Significant interaction effects between group and time were found in large TRL-P (F(1,43) = 10.16, p = 0.003) and LP-IR (F(1,42) = 4.28, p = 0.045). Post-hoc analyses revealed that the levels of large TRL-P (mean difference = 1.68, CI = [0.86, 2.51], p< .001) and LP-IR (mean difference = 5.67, CI = [1.15, 10.18], p = 0.015) significantly increased over time in the control group but while remained stable in the intervention group (mean difference = -0.15, CI = [-0.96, 0.66], p = 0.718; mean difference = -0.81, CI = [-5.22, 3.61], p = 0.714, respectively). Even when perceptions of psychological distress remain unchanged, incorporating gentle yoga poses and breathing exercises may reduce the risk of cardiometabolic disease in caregivers by inhibiting the development of insulin resistance. Standard lipids of cardiometabolic risk do not appear to be robust enough to detect short-term early changes of cardiometabolic risk in caregivers.

Trial registration: ClinicalTrials.gov Identifier: NCT02257853.

Relationship of American Heart Association's Life Simple 7, Ectopic Fat, and Insulin Resistance in 5 Racial/Ethnic Groups

BACKGROUND

The inverse association between ideal cardiovascular health (CVH) as measured by the American Heart Association's Life Simple 7 (LS7) and cardiovascular disease (CVD) incidence is well documented. However, research exploring the association between CVH and specific risk factors for cardiometabolic disease is sparse in diverse cohorts.

METHODS

This study included 7717 participants from the Mediators of Atherosclerosis in South Asians Living in America and the Multi-Ethnic Study of Atherosclerosis cohorts. We assigned each LS7 component a 0, 1, and 2 and summed these scores to derive an overall CVH score. Visceral, subcutaneous, and intermuscular fat area, pericardial fat volume, and hepatic fat attenuation were measured using noncontrast computed tomography. Multivariable linear regression was used to examine associations between CVH categories and each log-transformed ectopic fat depot, as well as the homeostatic assessment for insulin resistance (HOMA-IR).

RESULTS

In adjusted analysis, compared to those with ideal CVH, participants with poor CVH demonstrated 63.4% (95% CI, 54.3-73.0) higher visceral fat area, 84.0% (95% CI, 76.5-92.1) higher pericardial fat volume, 61.6% (95% CI, 50.7-73.2) higher subcutaneous fat area, and 40.6% (95% CI, 30.2-52.0) higher intermuscular fat area, and 15.1% (95% CI, 13.1-17.2) higher hepatic fat (all Ps < 0.001). Also, poor CVH was associated with 148.2% (95% CI, 131.1-166.7) higher HOMA-IR. We also found significant heterogeneity in the strengths of association by race/ethnicity for each ectopic fat depot.

CONCLUSION

Poor and intermediate CVH, as defined by LS7 metrics, were associated with significantly higher measures of ectopic fat and insulin resistance among individuals from 5 racial/ethnic groups.

Hiding unhealthy heart outcomes in a low-fat diet trial: the Women's Health Initiative Randomized Controlled Dietary Modification Trial finds that postmenopausal women with established coronary heart disease were at increased risk of an adverse outcome if they consumed a low-fat 'heart-healthy' diet

The Women’s Health Initiative Randomized Controlled Dietary Modification Trial (WHIRCDMT) was designed to test whether the US Department of Agriculture’s 1977 Dietary Guidelines for Americans protects against coronary heart disease (CHD) and other chronic diseases. The only significant finding in the original 2006 WHIRCDMT publication was that postmenopausal women with CHD randomised to a low-fat ‘heart-healthy’ diet in 1993 were at 26% greater risk of developing additional CHD events compared with women with CHD eating the control diet. A 2017 WHIRCDMT publication includes data for an additional 5 years of follow-up. It finds that CHD risk in this subgroup of postmenopausal women had increased further to 47%–61%. The authors present three post-hoc rationalisations to explain why this finding is ‘inadmissible’: (1) only women in this subgroup were less likely to adhere to the prescribed dietary intervention; (2) their failure to follow the intervention diet increased their CHD risk; and (3) only these women were more likely to not have received cholesterol-lowering drugs. These rationalisations appear spurious. Rather these findings are better explained as a direct consequence of postmenopausal women with features of insulin resistance (IR) eating a low-fat high-carbohydrate diet for 13 years. All the worst clinical features of IR, including type 2 diabetes mellitus (T2DM) in some, can be ‘reversed’ by the prescription of a high-fat low-carbohydrate diet. The Women’s Health Study has recently reported that T2DM (10.71-fold increased risk) and other markers of IR including metabolic syndrome (6.09-fold increased risk) were the most powerful predictors of future CHD development in women; blood low-density lipoprotein-cholesterol concentration was a poor predictor (1.38-fold increased risk). These studies challenge the prescription of the low-fat high-carbohydrate heart-healthy diet, at least in postmenopausal women with IR, especially T2DM. According to the medical principle of ‘first do no harm’, this practice is now shown to be not evidence-based, making it scientifically unjustifiable, perhaps unethical.

Compared to serum triglyceride alone, the association between serum triglyceride to high-density lipoprotein cholesterol ratio and 10-year cardiovascular disease risk as determined by Framingham risk scores in a large Korean cohort

BACKGROUND

The incidence of cardiovascular disease (CVD) has gradually increased to the extent that it has become the most common cause of mortality worldwide, and triglyceride/high-density lipoprotein cholesterol (TG/HDL) ratio, a surrogate marker of insulin resistance, has emerged as an independent predictor of CVD. Additionally, several recent studies have reported an independent association between triglyceride-rich lipoproteins and CVD risk. The present study was conducted to investigate the association between the CVD risk determined by the Framingham risk score and the TG alone and TG/HDL ratio in a large Korean cohort.

METHODS

This cross-sectional study included 6,995 participants aged 30 to 69 years that participated in a health examination program. TG/HDL ratio quartiles and TG quartiles were categorized as follows: Q1: ≤ 1.25, Q2: 1.26-2.07, Q3: 2.08-3.48, and Q4: ≥3.49; Q1: ≤ 71, Q2: 72-105, Q3: 106-159, and Q4: ≥160, respectively. Odds ratios (ORs) and 95% confidence intervals (CI) for high Framingham 10-year CVD risk (≥10%) were calculated across TG/HDL ratio quartiles and TG quartiles using multiple logistic regression analysis after adjusting for confounding variables.

RESULTS

The mean values of most cardiometabolic variables including body mass index, blood pressure, fasting plasma glucose levels, leukocyte count, median CRP levels, and Framingham 10-year CVD risk scores increased gradually with TG/HDL ratio quartiles. The OR (95% CI) of the highest TG/HDL ratio quartile and TG quartile as compared with the lowest TG/HDL ratio quartile and TG quartile for high Framingham 10-year CVD risk was 9.27 (6.68-12.86) and 0.97 (0.69-1.36) after adjusting for confounding variables, respectively.

CONCLUSION

Compared to TG, the TG/HDL ratio was found to be positively and independently associated with Framingham 10-year CVD risk in a large Korean cohort.

Disparities in cardio metabolic risk between Black and White women with polycystic ovary syndrome: a systematic review and meta-analysis

OBJECTIVE

We conducted a systematic review and meta-analysis to summarize and quantitatively pool evidence on cardiometabolic health disparities between Black and White women with polycystic ovary syndrome in the United States in response to the call for further delineation of these disparities in the international evidence-based guideline for the assessment and management of polycystic ovary syndrome.

DATA SOURCES

Databases of MEDLINE, Web of Science, and Scopus were searched initially through March 05, 2020, and confirmed on September 11, 2020.

STUDY ELIGIBILITY CRITERIA

Observational studies documenting cardiometabolic risk profile (glucoregulatory, lipid profile, anthropometric, and blood pressure status) in Black and White women with polycystic ovary syndrome were included. Studies on children (<17 years old) and pregnant or menopausal-aged women (>50 years) were excluded. The primary outcome was fasting glucose. Furthermore, data on major cardiovascular events (stroke, coronary heart disease, heart failure) and mortality rate (cardiovascular death, total mortality) were evaluated.

METHODS

Data were pooled by random-effects models and expressed as mean differences and 95% confidence intervals. Studies were weighted based on the inverse of the variance. Heterogeneity was evaluated by Cochran Q and I2 statistics. Study methodologic quality was assessed by the Newcastle-Ottawa scale.

RESULTS

A total of 11 studies (N=2851 [652 Black and 2199 White]) evaluated cardiometabolic risk profile and all had high quality (Newcastle-Ottawa scale score of ≥8). No studies reported on cardiovascular events and mortality rate. Black women had comparable fasting glucose (-0.61 [-1.69 to 2.92] mg/dL; I2=62.5%), yet exhibited increased fasting insulin (6.76 [4.97-8.56] μIU/mL; I2=59.0%); homeostatic model assessment of insulin resistance (1.47 [0.86-2.08]; I2=83.2%); systolic blood pressure (3.32 [0.34-6.30] mm Hg; I2=52.0%); and decreased triglyceride (-32.56 [-54.69 to -10.42] mg/dL; I2=68.0%) compared with White women (all, P≤.03). Groups exhibited comparable total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and diastolic blood pressure (all, P≥.06).

CONCLUSIONS

Black women with polycystic ovary syndrome have a greater tendency for an adverse cardiometabolic risk profile (increased insulin, homeostatic model assessment of insulin resistance, and systolic blood pressure) despite lower triglycerides than White women. Our observations support the consideration of these disparities for diagnostic, monitoring, and management practices in Black women and for future guideline recommendations. Given the heterogeneity among studies, future research should address the relative contributions of biologic, environmental, socioeconomic, and healthcare factors to the observed disparities. Furthermore, longitudinal research is required to address patient-pressing complications, including cardiovascular events and mortality rate in Black women with polycystic ovary syndrome as a high-risk yet understudied population.

Nanoparticle-Mediated Drug Delivery for the Treatment of Cardiovascular Diseases

Cardiovascular diseases (CVDs) are one of the foremost causes of high morbidity and mortality globally. Preventive, diagnostic, and treatment measures available for CVDs are not very useful, which demands promising alternative methods. Nanoscience and nanotechnology open a new window in the area of CVDs with an opportunity to achieve effective treatment, better prognosis, and less adverse effects on non-target tissues. The application of nanoparticles and nanocarriers in the area of cardiology has gathered much attention due to the properties such as passive and active targeting to the cardiac tissues, improved target specificity, and sensitivity. It has reported that more than 50% of CVDs can be treated effectively through the use of nanotechnology. The main goal of this review is to explore the recent advancements in nanoparticle-based cardiovascular drug carriers. This review also summarizes the difficulties associated with the conventional treatment modalities in comparison to the nanomedicine for CVDs.

Cardiometabolic Risk in Pre- and Post-Menopausal Women with Special Reference to Insulin Resistance: A Cross-Sectional Study

Background:

Reduced levels of estrogen have been associated with metabolic alterations and increased insulin resistance (IR) in postmenopausal women, thus predisposing them to cardiometabolic risks. The aim of this study was to assess alterations in parameters of cardiometabolic risk in apparently healthy pre- and post-menopausal women and to study the effect of IR on these metabolic parameters.

Methods:

A cross-sectional study was conducted on randomly selected apparently healthy women (n = 262). These women were categorized as premenopausal (n = 184) and postmenopausal (n = 78). Anthropometric measurements, blood pressure, lipid profile, fasting glucose, and insulin concentrations were estimated on all the participants using standard protocols. Homeostatic model assessment of IR was computed to estimate the level of IR.

Results:

Most lipid parameters, blood pressure, waist circumference, and fat percentage were significantly higher (P < 0.05) in postmenopausal women than premenopausal women. On subcategorizing women with respect to IR (<3, >3), metabolic parameters (e.g., triglyceride – 104.7 ±53.2 mg/dl, Blood Sugar Level Fasting (BSLF) – 103.3 ± 40.1 mg/dl, and fasting serum insulin – 23 ± 12.3 mIU/L) were also higher (P < 0.001) in premenopausal women having IR >3. Significantly higher low-density lipoprotein (132.7 ± 38.7 mg/dl vs. 114.4 ± 25 mg/dl) and total cholesterol (211.3 ± 40.5 vs. 184.8 ± 29.4 mg/dl) were observed in postmenopausal women with IR >3 (P < 0.05) along with higher BSLF (126.6±54.3 mg/dl**) and fasting insulin levels (22.3 ± 12.1 mIU/L) (P < 0.001).

Conclusion:

This study reveals that IR may predispose women to increased cardiometabolic risk. Urgent attention needs to be focused toward metabolic health of women.

Causal associations of insulin resistance with coronary artery disease and ischemic stroke: a Mendelian randomization analysis

INTRODUCTION

The relationship between insulin resistance (IR) and cardiovascular diseases is unclear. We aimed to examine the causal associations of IR with cardiovascular diseases, including coronary artery disease, myocardial infarction, ischemic stroke and its subtypes, using Mendelian randomization.

RESEARCH DESIGN AND METHODS

Due to low sample size for gold standard measures and in order to well reflect the underlying phenotype of IR, we used 53 single nucleotide polymorphisms associated with IR phenotypes (ie, fasting insulin, high-density lipoprotein cholesterol and triglycerides) from recent genome-wide association studies (GWASs) as instrumental variables. Summary-level data from four GWASs of European individuals were used. Data on IR phenotypes were obtained from meta-analysis of GWASs of up to 188 577 individuals and data on the outcomes from GWASs of up to 446 696 individuals. Mendelian randomization (MR) estimates were calculated with inverse-variance weighted, simple and weighted-median approaches and MR-Egger regression was used to explore pleiotropy.

RESULTS

Genetically predicted 1-SD increase in IR phenotypes were associated with a substantial increase in risk of coronary artery disease (OR=1.79, 95% CI: 1.57 to 2.04, p<0.001), myocardial infarction (OR=1.78, 95% CI: 1.54 to 2.06, p<0.001), ischemic stroke (OR=1.21, 95% CI: 1.05 to 1.40, p=0.007) and the small-artery occlusion subtype of stroke (OR=1.80, 95% CI: 1.30 to 2.49, p<0.001), but not associated with the large-artery atherosclerosis and cardioembolism subtypes of stroke. There was no evidence of pleiotropy. Results were broadly consistent in sensitivity analyses using simple and weighted-median approaches accounting for potential genetic pleiotropy.

CONCLUSIONS

This study provides evidence to support that IR was causally associated with risk of coronary artery disease, myocardial infarction, ischemic stroke and the small-artery occlusion subtype of stroke.

Low-intensity exercise in the prevention of cardiac insulin resistance-related inflammation and disturbances in NOS and MMP-9 regulation in fructose-fed ovariectomized rats

Exercise is important nonpharmacological treatment for improvement of insulin sensitivity in menopause. However, its effect on menopausal cardiac insulin resistance is needing further research. We investigated protective effects of low-intensity exercise on cardiac insulin signaling, inflammation, regulation of nitric oxide synthase (NOS) and matrix metalloproteinase 9 (MMP-9) in ovariectomized (OVX) Wistar rats, submitted to 10% fructose solution for 9 weeks. OVX rats were divided into control, sedentary fructose, and exercise fructose groups. Measurements of physical and biochemical characteristics were carried out to evaluate metabolic syndrome development. Messenger RNA and protein levels and phosphorylation of cardiac insulin signaling molecules, endothelial and inducible NOS (eNOS and iNOS), p65 subunit of nuclear factor κB (NFκB), tumor necrosis factor α (TNF-α), suppressor of cytokine signaling 3 (SOCS3), and MMP-9 were analyzed. Fructose increased insulin level, homeostasis model assessment (HOMA) index, and visceral adipose tissue weight, while low-intensity exercise prevented insulin level and HOMA index increase. Fructose also decreased cardiac pAkt (Ser473), peNOS (Ser1177) and increased insulin receptor substrate 1 (IRS1) phosphorylation at Ser307, pNFκB (Ser276) and NFκB and MMP-9 content, without any effect on iNOS, protein-tyrosine phosphatase 1B, TNF-α, and SOCS3. Exercise prevented changes in pIRS1 (Ser307), pAkt (Ser473), peNOS (Ser1177), pNFκB (Ser276), and NFκB expression. In addition, exercise increased pIRS1 (Tyr632), pAkt (Thr308), and eNOS expression. Low-intensity exercise prevented cardiac insulin signaling disarrangement in fructose-fed OVX rats and therefore eNOS dysfunction, as well as pro-inflammatory signaling activation, without effect on tissue remodeling, suggesting physical training as a way to reduce cardiovascular risk.

Early age at menarche is associated with insulin resistance: a systemic review and meta-analysis

OBJECTIVES

We aimed to conduct a systemic review and meta-analysis of the relevant studies to further investigate the association between age at menarche and insulin resistance.

METHODS

PubMed, EMBASE, and Web of Science (SCI) databases were systemically searched until December 2017. Observational studies comparing the incidences of insulin resistance in patients with early, average, and late menarchal ages were identified. Weighted mean difference (WMD) for HOMA-IR scores and fasting serum insulin levels in early vs late, early vs average. and average vs late comparisons were calculated with a random- or fixed-effects model.

RESULTS

A total of eight articles involving 5504 subjects were finally included. In the analysis of HOMA-IR, the pooled WMDs in five studies were 0.45 (95% confidence interval [CI] 0.31-0.60, p < 0.001), 0.40 (95% CI 0.28-0.52, p < 0.001), and -0.01 (95% CI -0.09 to 0.07, p = 0.854) for early vs late, early vs average, and average vs late comparisons, respectively. The fasting serum insulin levels in eight studies were analyzed, and it was significantly higher in subjects with earlier age at menarche (WMD 1.28, 95% CI 0.92-1.63, p < 0.001 for early vs late comparison, WMD 1.28, 95% CI 1.13-1.43, p < 0.001 for early vs average comparison) with mild and acceptable heterogeneity (I² = 42.5% and 7.4%, respectively). Publication bias was not detected via funnel plots and Egger's tests.

CONCLUSIONS

Our study revealed that earlier age at menarche was significantly associated with insulin resistance.

TRIAL REGISTRATION NUMBER

CRD42018083874.

Insulin resistance and cardiovascular outcomes in the ORIGIN trial

AIMS

In the Outcome Reduction with an Initial Glargine Intervention (ORIGIN) trial (Clinicaltrials.gov: NCT000069784), titrated doses of basal insulin glargine targeting fasting normoglycaemia had a neutral effect on cardiovascular outcomes. The dose of insulin required to achieve normoglycaemia provides a unique measurement of each individual's resistance to insulin's action, and was therefore used to examine the link between insulin resistance and cardiovascular outcomes.

MATERIALS AND METHODS

Self-titration of insulin doses targeting a fasting plasma glucose ≤5.3 mmoL/L (95 mg/dL) was promoted at every visit and cardiovascular and other serious health outcomes were ascertained. All analyses were restricted to participants allocated to insulin glargine, who added it to lifestyle or 1 glucose-lowering oral agent at randomization. Normoglycaemia was defined as a fasting plasma glucose <5.6 mmol/L and HbA1c <6% at the 2-year visit. The median of the natural logarithm of insulin doses (expressed per kg of fat-free mass), recorded at every visit from randomization until either the penultimate visit or the first occurrence of a cardiovascular outcome, was analysed.

RESULTS

Higher median insulin doses did not reflect incident cardiovascular events overall or in the subset that achieved normoglycaemia. When the dose taken before a cardiovascular event or the penultimate visit was analysed, the adjusted hazard of the composite of cardiovascular death, myocardial infarction or stroke was 0.94 (95% CI 0.88, 1.00) per unit higher dose overall, and 0.91 (95% CI 0.81, 1.01) in the normoglycaemic subset.

CONCLUSIONS

Insulin resistance may not promote cardiovascular outcomes in individuals with dysglycaemia.

Relationship between estimated cardiovascular disease risk and insulin resistance in a black African population living with HIV: a cross-sectional study from Cameroon

OBJECTIVES

Cardiovascular disease (CVD) and metabolic diseases are growing concerns among patients with HIV infection as a consequence of the improving survival of this population. We aimed to assess the relationship between CVD risk and insulin resistance in a group of black African individuals with HIV infection.

METHODS

This cross-sectional study involved patients with HIV infection aged 30-74 years and followed up at the Yaoundé Central Hospital, Cameroon. Absolute CVD risk was calculated using the Framingham and the DAD CVD risk equations while the HOMA-IR index was used to assess insulin resistance (index ≥2.1).

RESULTS

A total of 452 patients (361 women; 80%) were screened. The mean age was 44.4 years and most of the respondents were on antiretroviral therapy (88.5%). The median 5-year cardiovascular risk was 0.7% (25th-75th percentiles: 0.2-2.0) and 0.6% (0.3-1.3) according to the Framingham and DAD equations respectively. Of all participants, 47.3% were insulin resistant. The Framingham equation derived absolute CVD risk was significantly associated with insulin resistance; while no linear association was found using the DAD equation.

CONCLUSION

The relationship between cardiovascular risk and insulin resistance in black African patients with HIV infection seems to depend on the cardiovascular risk equation used.

Gold nanoparticle-based miR155 antagonist macrophage delivery restores the cardiac function in ovariectomized diabetic mouse model

Diabetic cardiomyopathy is a common disease in postmenopausal women, in whom the estrogen deficiency aggravates the pathology. In this study, we have found that estrogen deficiency due to ovariectomy aggravates the inflammation in the hearts of diabetic mice, as depicted by excessive proinflammatory type 1 macrophages (M1) over anti-inflammatory type 2 macrophages (M2). Accordingly, an additional increase of reactive oxygen species, cell apoptosis, cardiac hypertrophy, and fibrosis was observed in the hearts of ovariectomized diabetic mice, in comparison with the diabetes-only group. Significantly, miR155, a potent promoter of M1 polarization, was found to be additionally enhanced in the macrophages and hearts by ovariectomy. Tail vein injection of miR155-AuNP, in which thiol-modified antago-miR155 was covalently conjugated with gold nanoparticle (AuNP), preferentially delivered the nucleic acids into the macrophages via phagocytosis. Together with the increased M2 ratio and reduced inflammation, in vivo delivery of antago-miR155 reduced cell apoptosis and restored the cardiac function. The restoration efficacy of miR155-AuNP was much better than general macrophage depletion by clodrosome. In summary, we revealed that M1/M2 imbalance contributes to the aggravated cardiomyopathy in ovariectomized diabetic mice, and therapeutically reducing miR155 in macrophages by AuNP serves as a promising strategy in improving cardiac function.

Imbalanced insulin action in chronic over nutrition: Clinical harm, molecular mechanisms, and a way forward

The growing worldwide prevalence of overnutrition and underexertion threatens the gains that we have made against atherosclerotic cardiovascular disease and other maladies. Chronic overnutrition causes the atherometabolic syndrome, which is a cluster of seemingly unrelated health problems characterized by increased abdominal girth and body-mass index, high fasting and postprandial concentrations of cholesterol- and triglyceride-rich apoB-lipoproteins (C-TRLs), low plasma HDL levels, impaired regulation of plasma glucose concentrations, hypertension, and a significant risk of developing overt type 2 diabetes mellitus (T2DM). In addition, individuals with this syndrome exhibit fatty liver, hypercoagulability, sympathetic overactivity, a gradually rising set-point for body adiposity, a substantially increased risk of atherosclerotic cardiovascular morbidity and mortality, and--crucially--hyperinsulinemia. Many lines of evidence indicate that each component of the atherometabolic syndrome arises, or is worsened by, pathway-selective insulin resistance and responsiveness (SEIRR). Individuals with SEIRR require compensatory hyperinsulinemia to control plasma glucose levels. The result is overdrive of those pathways that remain insulin-responsive, particularly ERK activation and hepatic de-novo lipogenesis (DNL), while carbohydrate regulation deteriorates. The effects are easily summarized: if hyperinsulinemia does something bad in a tissue or organ, that effect remains responsive in the atherometabolic syndrome and T2DM; and if hyperinsulinemia might do something good, that effect becomes resistant. It is a deadly imbalance in insulin action. From the standpoint of human health, it is the worst possible combination of effects. In this review, we discuss the origins of the atherometabolic syndrome in our historically unprecedented environment that only recently has become full of poorly satiating calories and incessant enticements to sit. Data are examined that indicate the magnitude of daily caloric imbalance that causes obesity. We also cover key aspects of healthy, balanced insulin action in liver, endothelium, brain, and elsewhere. Recent insights into the molecular basis and pathophysiologic harm from SEIRR in these organs are discussed. Importantly, a newly discovered oxide transport chain functions as the master regulator of the balance amongst different limbs of the insulin signaling cascade. This oxide transport chain--abbreviated 'NSAPP' after its five major proteins--fails to function properly during chronic overnutrition, resulting in this harmful pattern of SEIRR. We also review the origins of widespread, chronic overnutrition. Despite its apparent complexity, one factor stands out. A sophisticated junk food industry, aided by subsidies from willing governments, has devoted years of careful effort to promote overeating through the creation of a new class of food and drink that is low- or no-cost to the consumer, convenient, savory, calorically dense, yet weakly satiating. It is past time for the rest of us to overcome these foes of good health and solve this man-made epidemic.