Influence of menopause and cholesteryl ester transfer protein (CETP) TaqIB polymorphism on lipid profile and HDL subpopulations distribution in women with and without type 2 diabetes

Severe Hypertriglyceridemia in Patients with Type 2 Diabetes Mellitus Participating in the AMD Annals Initiative

Background: Familial chylomicronemia syndrome (FCS) is a rare inherited condition due to lipoprotein lipase deficiency, characterized by hyperchylomicronemia and severe hypertriglyceridemia. Diagnosis is often delayed, thus increasing the risk of acute pancreatitis and hospitalization. Hypertriglyceridemia is a common finding in patients with type 2 diabetes (T2D), who may harbor FCS among the most severe forms. Aim of the Study: We investigated the prevalence and clinical characteristics associated with severe hypertriglyceridemia in a range indicative of FCS, in a large population of subjects with T2D. Methods: Within the large population of the AMD Annals Initiative, patients with T2D with a lipid profile suggestive of FCS [triglycerides >880 mg/dL and/or high-density lipoprotein (HDL)-cholesterol <22 mg/dL or non-HDL-cholesterol ≤70 mg/dL] and their clinical features have been identified. Results: Overall, 8592 patients had triglyceride values >880 mg/dL in a single examination, 613 in two examinations, and 34 in three or more measurements. Patients with high triglyceride levels were mostly male (80%), with a relatively young age (54 years), short duration of diabetes (6.3 years), and elevated hemoglobin A1c (HbA1c) levels (9.4%). By stratifying this group of patients according to the severity of hypertriglyceridemia, more severe hypertriglyceridemia (triglyceride levels ≥2000 mg/dL) was associated with an even younger age (52 vs. 54 years), even higher mean HbA1c values (10.0% vs. 9.4%), and significantly higher HDL-cholesterol levels (37.9 vs. 32.4 mg/dL; P < 0.0001). Patients with persistently elevated triglyceride levels (n = 34), on three measurements, had a younger age; lower body mass index, HbA1c, and HDL-cholesterol levels; more frequent use of fibrates and insulin; and a higher prevalence of major cardiovascular events. Conclusions: Severe hypertriglyceridemia is a frequent condition in outpatients with T2D participating in the AMD Annals Initiative, and it is associated with male sex, young age, short disease duration, and a worse glycemic profile. Among patients with persistent severe hypertriglyceridemia, hidden FCS may be present.

Gender Differences in Insulin Resistance: New Knowledge and Perspectives

Insulin resistance is the main mechanism in a whole series of pathological conditions, which are not only of metabolic interest but also of a systemic type. This phenomenon means that the body's cells become less sensitive to the hormone insulin, leading to higher levels of insulin in the blood. Insulin resistance is a phenomenon that can be found in both men and women and in particular, in the latter, it is found mainly after menopause. Premenopause, hormonal fluctuations during the menstrual cycle, and the presence of estrogen can affect insulin sensitivity. Androgens, such as testosterone, are typically higher in men and can contribute to insulin resistance. In both sexes, different human body types affect the distribution and location of body fat, also influencing the development of diabetes and cardiovascular disease. Insulin resistance is also associated with some neurological and neurogenerative disorders, polycystic ovary syndrome, atherosclerosis, and some of the main neoplastic pathologies. A healthy lifestyle, including regular physical activity, a balanced diet, and self-maintenance, can help to prevent the onset of insulin resistance, regardless of gender, although the different habits between men and women greatly affect the implementation of preventative guidelines that help in fighting the manifestations of this metabolic disorder. This review may help to shed light on gender differences in metabolic diseases by placing a necessary focus on personalized medical management and by inspiring differentiated therapeutic approaches.

Crosstalk between high-density lipoproteins and endothelial cells in health and disease: Insights into sex-dependent modulation

Atherosclerotic cardiovascular disease is the leading cause of death worldwide. Intense research in vascular biology has advanced our knowledge of molecular mechanisms of its onset and progression until complications; however, several aspects of the patho-physiology of atherosclerosis remain to be further elucidated. Endothelial cell homeostasis is fundamental to prevent atherosclerosis as the appearance of endothelial cell dysfunction is considered the first pro-atherosclerotic vascular modification. Physiologically, high density lipoproteins (HDLs) exert protective actions for vessels and in particular for ECs. Indeed, HDLs promote endothelial-dependent vasorelaxation, contribute to the regulation of vascular lipid metabolism, and have immune-modulatory, anti-inflammatory and anti-oxidative properties. Sex- and gender-dependent differences are increasingly recognized as important, although not fully elucidated, factors in cardiovascular health and disease patho-physiology. In this review, we highlight the importance of sex hormones and sex-specific gene expression in the regulation of HDL and EC cross-talk and their contribution to cardiovascular disease.

Atherogenic dyslipidemia and diabetic nephropathy

Chronic kidney disease is associated with altered lipid metabolism and lipid accumulation. Although it is though that hyperlipemia is a consequence of kidney dysfunction, several lines of evidence support that hyperlipidemia may contribute to the onset and progression of kidney disease, also in diabetes. This review describes the results of recent observational studies supporting the concept that glucose is only partly responsible for kidney damage onset, while a cluster of factors, including hypertriglyceridemia and low HDL-cholesterol, could play a relevant role in inducing onset and progression of DKD. We also report the results of randomized clinical trials investigating in type 2 diabetic patients the role of drug improvement of hypertriglyceridemia on renal outcomes. Finally, we discuss putative mechanisms linking hyperlipidemia (i.e. hypertriglyceridemia or low HDL cholesterol) with kidney disease.

Natural history and risk factors for diabetic kidney disease in patients with T2D: lessons from the AMD-annals

The Associazione Medici Diabetologi (AMD) annals initiative is an ongoing observational survey promoted by AMD. It is based on a public network of about 700 Italian diabetes clinics, run by specialists who provide diagnostic confirmation and prevention and treatment of diabetes and its complications. Over the last few years, analysis of the AMD annals dataset has contributed several important insights on the clinical features of type-2 diabetes kidney disease and their prognostic and therapeutic implications. First, non-albuminuric renal impairment is the predominant clinical phenotype. Even though associated to a lower risk of progression compared to overt albuminuria, it contributes significantly to the burden of end-stage renal disease morbidity. Second, optimal blood pressure control provides significant but incomplete renal protection. It reduces albuminuria but there may be a J curve phenomenon with eGFR at very low blood pressure values. Third, hyperuricemia and diabetic hyperlipidemia, namely elevated triglycerides and low HDL cholesterol, are strong independent predictors of chronic kidney disease (CKD) onset in diabetes, although the pathogenetic mechanisms underlying these associations remain uncertain. Fourth, the long-term intra-individual variability in HbA1c, lipid parameters, uric acid and blood pressure plays a greater role in the appearance and progression of CKD than the absolute value of each single variable. These data help clarify the natural history of CKD in patients with type 2 diabetes and provide important clues for designing future interventional studies.

Beta cell stress in a 4-year follow-up of patients with type 2 diabetes: A longitudinal analysis of the BetaDecline Study

BACKGROUND

Type 2 diabetes mellitus (T2DM) is associated with a progressive deterioration in beta cell function and loss of glycaemic control. Clinical predictors of beta cell failure are needed to guide appropriate therapy.

METHODS

A prospective evaluation of a large set of potential predictors of beta cell stress, measured as change in the proinsulin/insulin (PI/I) ratio, was conducted in a cohort of 235 outpatients with T2DM on stable treatment with oral hypoglycaemic agents or diet followed up for ~4 years (median value 3.9 years; interquartile range 3.8-4.1 years).

RESULTS

Overall, metabolic control deteriorated over time, with a significant increase in glycated haemoglobin (HbA1c; P < .0001), proinsulin (P < .0001), and PI/I ratio (P = .001), without significant changes in the homeostatic model assessment of insulin resistance. Multivariate regression analysis showed that for each 1% (10.9 mmol/mol) increase from baseline in HbA1c, the risk of beta cell stress increased by 3.8 times; for each 1% (10.9 mmol/mol) incremental increase in HbA1c during the study, risk of beta cell stress increased by 2.25 times that at baseline. By contrast, baseline anthropometric and clinical variables, lipid profile, inflammatory markers (PCR, IL-6), non-esterified fatty acids, and current therapies did not independently influence PI/I ratio variation during follow-up.

CONCLUSIONS

In this cohort of patients with T2DM, beta cell function progressively deteriorated despite current therapies. Among a large set of clinical and biochemical predictors, only baseline HbA1c levels and their deterioration overtime were associated with higher beta cell stress over time.

HDL subclasses and the common CETP TaqIB variant predict the incidence of microangiopatic complications in type 2 diabetic women: A 9years follow-up study

AIMS

Diabetic kidney disease (DKD) and retinopathy (DR) develop in a considerable number of subjects with Type 2 Diabetes (T2D) despite the achievement of the recommended targets for glycaemia and blood pressure. Atherogenic dyslipidemia may play a relevant role, especially in T2DM women.

METHODS

We report our findings on the effect of diabetic dyslipidaemia, the HDL subclasses distribution and the common cholesteryl ester transfer protein (CETP)TaqIB variant on the incidence or the progression of DKD and DR in 97 T2D women, after a ∼9years of follow-up.

RESULTS

At baseline, T2D women presented with low HDL-C levels and higher levels of large lipid rich α-1 (16.34mg/dl), α-2 (33.39mg/dl) and pre- α1 (4.81mg/dl) HDL subparticles. The CETP TaqIB polymorphism and baseline HbA1c, triglycerides, and HDL-C levels as well as specific HDL subpopulations were associated to the occurrence of RD after ∼9years of follow-up. At stepwise regression analysis, HbA1c, triglycerides and the less atheroprotective α-3 HDL particles were the only factors independently associated to the incidence of RD. These same variables were also associated with the progression from background to proliferative RD. BMI, LDL/HDL ratio and low levels of α-1 HDL particles were associated to the occurrence of DKD at univariate analysis, although BMI was the only significant predictor at stepwise multivariate regression analysis.

CONCLUSIONS

In T2D women, atherogenic dyslipidemia as well as subtle modifications in lipoprotein particles profile are associated with incidence and progression of microvascular disease.

Germain A, Egede LE. Trends in sex differences in the receipt of quality of care indicators among adults with diabetes: United States 2002-2011

BACKGROUND

Evidence suggests disparities in quality of care (QoC) indicators based on sex exist in adults diagnosed with diabetes; however, this research is limited. Therefore, the objective of this research study was to assess differences in QOC indicators in a nationally representative sample of men and women with diabetes.

METHODS

Cross-sectional study of 17,702 men and women (≥18 years of age) with diabetes from the 2002-2011 Medical Expenditure Panel Survey Household Component. Sex was the main predictor variable, and the dependent variables were five binary indicators to measure QOC, which included testing of hemoglobin A1c, examining feet annually, getting eyes dilated, checking blood pressure, and visiting the doctor annually. Sample demographics by sex were assessed. Unadjusted analyses were computed for descriptive statistics by sex and proportions of QOC indicators over time. Logistic regression evaluated associations between QOC indicators and sex, while controlling for sociodemographic characteristics, time, and comorbid conditions.

RESULTS

Approximately 44% and 56% of the sample was comprised of men and women, respectively. Unadjusted analyses showed significant differences in A1c testing (p < 0.001) and foot examinations (p = 0.002) for the entire sample, and significant differences in A1c testing (p = 0.027), foot examinations (p = 0.01), and dilated eye exams (p = 0.026) among men and A1c testing (p < 0.001) among women overtime. Adjusted analyses found women to be significantly more likely to have dilated eye examinations during a given year (OR = 1.14; 95% CI 1.04, 1.24), to get their blood pressure checked by a doctor in a given year (OR = 1.44; 95% CI 1.13, 1.84), and to visit a doctor annually (OR = 1.39; 95% CI 1.22, 1.58) compared to men.

CONCLUSIONS

In this sample of adults with diabetes, women had significantly higher odds of receiving quality of care compared to men. These findings suggest the importance of educating patients about appropriate metrics of diabetes management, especially men, and the need for continuous empowerment of women to receive proper and optimal care. Additional research is needed to identify causes and reduce sex and gender disparities associated with diabetes quality of care.

Plasma Triglycerides and HDL-C Levels Predict the Development of Diabetic Kidney Disease in Subjects With Type 2 Diabetes: The AMD Annals Initiative

OBJECTIVE

Despite the achievement of blood glucose, blood pressure, and LDL cholesterol (LDL-C) targets, the risk for diabetic kidney disease (DKD) remains high among patients with type 2 diabetes. This observational retrospective study investigated whether diabetic dyslipidemia-that is, high triglyceride (TG) and/or low HDL cholesterol (HDL-C) levels-contributes to this high residual risk for DKD.

RESEARCH DESIGN AND METHODS

Among a total of 47,177 patients attending Italian diabetes centers, 15,362 patients with a baseline estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m², normoalbuminuria, and LDL-C ≤130 mg/dL completing a 4-year follow-up were analyzed. The primary outcome was the incidence of DKD, defined as either low eGFR (<60 mL/min/1.73 m²) or an eGFR reduction >30% and/or albuminuria.

RESULTS

Overall, 12.8% developed low eGFR, 7.6% an eGFR reduction >30%, 23.2% albuminuria, and 4% albuminuria and either eGFR <60 mL/min/1.73 m² or an eGFR reduction >30%. TG ≥150 mg/dL increased the risk of low eGFR by 26%, of an eGFR reduction >30% by 29%, of albuminuria by 19%, and of developing one abnormality by 35%. HDL-C <40 mg/dL in men and <50 mg/dL in women were associated with a 27% higher risk of low eGFR and a 28% risk of an eGFR reduction >30%, with a 24% higher risk of developing albuminuria and a 44% risk of developing one abnormality. These associations remained significant when TG and HDL-C concentrations were examined as continuous variables and were only attenuated by multivariate adjustment for numerous confounders.

CONCLUSIONS

In a large population of outpatients with diabetes, low HDL-C and high TG levels were independent risk factors for the development of DKD over 4 years.

Association of the CETP Taq1B and LIPG Thr111Ile Polymorphisms with Glycated Hemoglobin and Blood Lipids in Newly Diagnosed Hyperlipidemic Patients

OBJECTIVE

To examine the association of 2 common polymorphisms in high-density lipoprotein (HDL)-related genes, namely, cholesterol ester transfer protein CETP Taq1B (rs708272) and endothelial lipase LIPG Thr111Ile (rs2000813), with glycated hemoglobin (A1C), blood lipid levels and the risk for type 2 diabetes in a group of hyperlipidemic patients from northern Greece.

METHODS

We categorized 175 patients with hyperlipidemia into 2 subgroups according to the presence or absence of type 2 diabetes, defined as a recent diagnosis, A1C >6.5% and/or fasting glucose >126 mg/dL. Genotypes for the 2 polymorphisms studied were determined by polymerase chain reaction-restriction fragment length polymorphism. Both polymorphisms were analyzed by multivariate and univariate analyses of baseline A1C levels and plasma lipids. The genotype and allele frequencies of the 2 subgroups were compared.

RESULTS

The CETP Taq1B polymorphism was associated with HDL-cholesterol (HDL-C) and A1C levels, but this association was affected by type 2 diabetes; the association with A1C levels was significant only in type 2 diabetes (p=0.005), whereas the association with HDL-C occurred only in the subgroup without type 2 diabetes (p<0.001). LIPG Thr111Ile did not affect plasma HDL-C or A1C levels independently but appeared to modulate their association with CETP Taq1B, and LIPG 111IleIle homozygotes tended to be present at a higher frequency in the hyperlipidemic patients with type 2 diabetes compared to the hyperlipidemic patients without type 2 diabetes (p=0.056).

CONCLUSIONS

In hyperlipidemic patients, apart from its known association with HDL-C, CETP Taq1B is also associated with A1C levels, and both associations are modified by type 2 diabetes and LIPG Thr111Ile.

Age- and Gender-Related Differences in LDL-Cholesterol Management in Outpatients with Type 2 Diabetes Mellitus

Background. Dyslipidemia contribute to the excess of coronary heart disease (CHD) risk observed in women with type 2 diabetes (T2DM). Low density lipoprotein-cholesterol (LDL-C) is the major target for CHD prevention, and T2DM women seem to reach LDL-C targets less frequently than men. Aim. To explore age- and gender-related differences in LDL-C management in a large sample of outpatients with T2DM. Results. Overall, 415.294 patients (45.3% women) from 236 diabetes centers in Italy were included. Women were older and more obese, with longer diabetes duration, higher total-cholesterol, LDL-C, and HDL-C serum levels compared to men (P < 0.0001). Lipid profile was monitored in ~75% of subjects, women being monitored less frequently than men, irrespective of age. More women did not reach the LDL-C target as compared to men, particularly in the subgroup treated with lipid-lowering medications. The between-genders gap in reaching LDL-C targets increased with age and diabetes duration, favouring men in all groups. Conclusions. LDL-C management is worst in women with T2DM, who are monitored and reach targets less frequently than T2DM men. Similarly to men, they do not receive medications despite high LDL-C. These gender discrepancies increase with age and diabetes duration, exposing older women to higher CHD risk.

Lipid and non-lipid cardiovascular risk factors in postmenopausal type 2 diabetic women with and without coronary heart disease

BACKGROUND

Coronary heart disease (CHD) is the leading cause of death in diabetic women. In addition to hyperglycemia, other factors may contribute to the excessive cardiovascular risk.

AIM

In this study we evaluated common and emerging risk factors in a selected group of postmenopausal type 2 diabetic women with (n = 36) and without CHD (n = 59), not taking lipid-lowering medications.

METHODS

Clinical and lifestyle data were collected, and metabolic and lipid profile, as well as fasting plasma levels of total homocysteine (tHcy), folate, vitamin B12, C-reactive protein (hsCRP), interleukin 6 (IL-6), and vascular cell adhesion molecule-1 (VCAM-1) were measured in all participants.

RESULTS

Age, menopause and diabetes duration, family history for cardiovascular disease, prevalence of hypertension and current insulin use were greater in diabetic women with than without CHD (P < 0.05 for all comparisons). CHD women also showed higher levels of triglycerides, small dense LDL (sdLDL), remnant-like particle cholesterol, tHcy, and VCAM-1, and a lower creatinine clearance (P < 0.05 all). Conversely, the two groups were comparable for BMI, waist circumference, smoking habit, fasting plasma glucose, HbA1c, total cholesterol, low-density lipoprotein cholesterol (LDL-C), HDL cholesterol, folate, vitamin B12, hsCRP and IL-6 levels. At multivariate analysis, lower creatinine clearance (OR = 0.932, P = 0.017) and higher sdLDL serum concentration (OR = 1.224, P = 0.037) were the strongest risk factors associated with CHD in this population, whereas no significant association was noted with LDL-C.

CONCLUSIONS

Our data suggest that beyond LDL-C, a lower creatinine clearance and more subtle alterations of LDL particles, together with a constellation of several well known and emerging cardiovascular risk factors, are stronger contributors to the high CHD risk of diabetic women.

Markers of Systemic Inflammation and Apo-AI Containing HDL Subpopulations in Women with and without Diabetes

Background. Besides their role in reverse cholesterol transport, HDL particles may affect the atherosclerotic process through the modulation of subclinical inflammation. HDL particles differ in size, composition, and, probably, anti-inflammatory properties. This hypothesis has never been explored in diabetic women, frequently having dysfunctional HDL. The potential relationship between lipid profile, Apo-AI containing HDL subclasses distribution, and common inflammatory markers (hsCRP, IL-6) was examined in 160 coronary heart disease- (CHD-) free women with and without type 2 diabetes. Results. Compared to controls, diabetic women showed lower levels of the atheroprotective large α-1, α-2, and pre-α-1 and higher concentration of the small, lipid-poor α-3 HDL particles (P < 0.05 all); diabetic women also had higher hsCRP and IL-6 serum levels (age- and BMI-adjusted P < 0.001). Overall, HDL subclasses significantly correlated with inflammatory markers: hsCRP inversely correlated with α-1 (P = 0.01) and pre-α-1 (P = 0.003); IL-6 inversely correlated with α-1 (P = 0.003), α-2 (P = 0.004), and pre-α-1 (P = 0.002) and positively with α-3 HDL (P = 0.03). Similar correlations were confirmed at univariate regression analysis. Conclusions. More atheroprotective HDL subclasses are associated with lower levels of inflammatory markers, especially in diabetic women. These data suggest that different HDL subclasses may influence CHD risk also through the modulation of inflammation.

Diabetes abrogates sex differences and aggravates cardiometabolic risk in postmenopausal women

Background

The aim of this study is to evaluate the effect of gender and menopause in cardiometabolic risk in a type 2 diabetes mellitus (T2DM) population, based on classical and non-traditional markers.

Methods

Seventy four volunteers and 110 T2DM patients were enrolled in the study. Anthropometric data, blood pressure, body mass index (BMI), waist circumference (WC) and the following serum markers were analyzed: glucose, Total-c, TGs, LDL-c, Oxidized-LDL, total HDL-c and large and small HDL-c subpopulations, paraoxonase 1 activity, hsCRP, uric acid, TNF-α, adiponectin and VEGF.

Results

Non-diabetic women, compared to men, presented lower glycemia, WC, small HDL-c, uric acid, TNF-α and increased large HDL-c. Diabetes abrogates the protective effect of female gender, since diabetic women showed increased BMI, WC, small HDL-c, VEGF, uric acid, TNF-α and hsCRP, as well as reduced adiponectin, when compared with non-diabetic. In diabetic females, but not in males, WC is directly and significantly associated with TNF-α, VEGF, hsCRP and uric acid; TNF-α is directly associated with VEGF and hsCRP, and inversely with adiponectin. Postmenopausal females presented a worsen cardiometabolic profile, viewed by the increased WC, small HDL-c, VEGF, uric acid, TNF-α and hsCRP. In this population, WC is directly and significantly associated with TNF-α, VEGF, hsCRP; TNF-α is directly associated with VEGF; and uric acid is inversely associated with large HDL-c and hsCRP with adiponectin, also inversely.

Conclusions

Diabetes abrogates the protective effect of gender on non-diabetic women, and postmenopausal diabetic females presented worsen cardiometabolic risk, including a more atherogenic lipid sketch and a pro-inflammatory and pro-angiogenic profile. The classical cardiovascular risk factors (CVRFs) fail to completely explain these differences, which are better clarified using “non-traditional” factors, such as HDL-c subpopulations, rather than total HDL-c content, and markers of inflammation and angiogenesis, namely TNF-α, hsCRP, uric acid and VEGF. Multi-therapeutic intervention, directed to obesity, atherogenic lipid particles and inflammatory mediators is advisory in order to efficiently prevent the serious diabetic cardiovascular complications.