Hyperlipidemia Influences the Accuracy of Glucometer-Measured Blood Glucose Concentrations in Genetically Diverse Mice

The Genetic Elements of the Obesity Paradox in Atherosclerosis Identified in an Intercross Between Hyperlipidemic Mouse Strains

Overweight and obese individuals show lower mortality rates or better prognoses than those of normal weight in a variety of diseases, a phenomenon called the "obesity paradox". An inverse association of adiposity with atherosclerosis has been observed in both humans and mice. To dissect phenotypic and genetic connections between the traits, 154 female and 145 male F2 mice were generated from an intercross between BALB/cJ and LP/J apolipoprotein E-deficient mice and fed a Western diet for 12 weeks. Atherosclerotic lesion size in the aortic root, body weight, plasma lipids, and glucose were measured, and genotyping was performed on miniMUGA SNP arrays. Quantitative trait locus (QTL) analyses on all F2 mice with sex as a covariate revealed four significant QTLs on chromosomes (Chr) 3, 6, 13, and 15 for atherosclerosis and three significant QTLs on Chr2, 7, and 15 for body weight. Chr15 QTL for atherosclerosis overlapped with one for body weight near 36 Mb. After adjusting for variation in body weight, Chr15 atherosclerosis QTL was downgraded from significant to suggestive linkage. Body weight was inversely correlated with atherosclerotic lesion sizes and accounted for more variance than a single other risk factor for atherosclerosis among F2 mice. Analysis of public data collected from two backcross cohorts revealed strong correlations between body weight and fat mass in adult mice (r ≥ 0.93; p ≤ 1.6 × 10-136). Thus, the obesity paradox in atherosclerosis is partially attributable to shared genetic components that have an opposite effect on adiposity and atherosclerosis.

The association between blood glucose levels and lipids in the general adult population: results from NHANES (2005-2016)

OBJECTIVE

Although abnormal lipid metabolism is one of the major risk factors for diabetes, the correlation between lipids and glucose is rarely discussed in the general population. The differences in lipid-glucose correlations across gender and ethnicity have been even more rarely studied. We examined the association between fasting blood glucose (FBG) and lipids, including triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and apolipoprotein B (ApoB), using 6,093 participants aged 20 years or older from the National Health and Nutrition Examination Survey (NHANES).

METHODS

Analyses were performed using multiple logistic regression and generalised additive models.

RESULTS

When other confounders were considered, we found that fasting glucose was positively correlated with triglycerides and negatively correlated with HDL-C, whereas total cholesterol, LDL-C cholesterol, and fasting glucose were related to each other in a U-curve fashion, with inflection points of 5.17 mmol/L and 2.3 mmol/L, respectively.This relationship persisted in subgroups of different sexes and races. A positive correlation was found between fasting glucose and ApoB, but subgroup analyses revealed that this relationship was not correlated across gender and race.

CONCLUSION

In the general population, fasting blood glucose levels were positively correlated with TG, negatively correlated with HDL-C, and U-shaped with total cholesterol and LDL-C. The likelihood of developing diabetes was 40% higher when LDL-C was greater than 2.3 mmol/L than in patients with LDL-C less than 2.3 mmol/L.

Phenotypic and Genetic Evidence for a More Prominent Role of Blood Glucose than Cholesterol in Atherosclerosis of Hyperlipidemic Mice

Hyperlipidemia and type 2 diabetes (T2D) are major risk factors for atherosclerosis. Apoe-deficient (Apoe−/−) mice on certain genetic backgrounds develop hyperlipidemia, atherosclerosis, and T2D when fed a Western diet. Here, we sought to dissect phenotypic and genetic relationships of blood lipids and glucose with atherosclerotic plaque formation when the vasculature is exposed to high levels of cholesterol and glucose. Male F2 mice were generated from LP/J and BALB/cJ Apoe−/− mice and fed a Western diet for 12 weeks. Three significant QTL Ath51, Ath52 and Ath53 on chromosomes (Chr) 3 and 15 were mapped for atherosclerotic lesions. Ath52 on proximal Chr15 overlapped with QTL for plasma glucose, non-HDL cholesterol, and triglyceride. Atherosclerotic lesion sizes showed significant correlations with fasting, non-fasting glucose, non-fasting triglyceride, and body weight but no correlation with HDL, non-HDL cholesterol, and fasting triglyceride levels. Ath52 for atherosclerosis was down-graded from significant to suggestive level after adjustment for fasting, non-fasting glucose, and non-fasting triglyceride but minimally affected by HDL, non-HDL cholesterol, and fasting triglyceride. Adjustment for body weight suppressed Ath52 but elevated Ath53 on distal Chr15. These results demonstrate phenotypic and genetic connections of blood glucose and triglyceride with atherosclerosis, and suggest a more prominent role for blood glucose than cholesterol in atherosclerotic plaque formation of hyperlipidemic mice.

Study of the Significance of Thromboelastography Changes in Patients with Dyslipidemia

Purpose

To investigate the changes in thromboelastography (TEG) in patients with dyslipidemia to study its effect on the blood coagulation status.

Methods

131 patients hospitalized in Fujian Provincial Jinshan Hospital from January 2018 to December 2020 were selected, and 64 cases in the hyperlipidemia (HL) group and 67 cases in the non-HL group were set according to whether their blood lipids were abnormal. By measuring the changes of each parameter of TEG in patients, the relevant parameters R value, K value, α angle, and MA value were calculated. And routine blood coagulation (PT, APTT, INR, FIB, and TT) and routine blood (platelet count) tests were performed on all study subjects to analyze the changes of each index of the coagulation function and each parameter of TED in both groups and explore the clinical value of TEG on HL diseases.

Results

Compared with the non-HL group, R and K values decreased, and angle and MA values increased in the HL group (P < 0.05). PT, APTT, and INR values decreased, and FIB values increased in the HL group compared with the nonhyperlipidemic group (P < 0.05). The TT levels were similar in the non-HL group and the HL group (P > 0.05). Compared with the non-HL group, PLT values decreased, and PDW and MPV values increased in the HL group (P < 0.05). R value was positively correlated with APTT, r= 0.373, P=0.002. K value was negatively correlated with PLT, r= -0.399, P=0.002. α angle and MA values were positively correlated with PLT, r= 0.319/0.475, P=0.010/P < 0.001. The rest of the indexes did not correlate with each parameter of TEG significant correlation.

Conclusion

TEG can predict the hypercoagulability and hypocoagulability of blood by the changes of R value, K value, α angle, and MA to evaluate the effect of hyperlipidemia on the coagulation status, which is important for guiding the adjustment of lipid-lowering, antithrombotic, and anticoagulation programs in patients with atherosclerosis combined with hyperlipidemia or postsurgery combined with hyperlipidemia.

Ldlr-Deficient Mice with an Atherosclerosis-Resistant Background Develop Severe Hyperglycemia and Type 2 Diabetes on a Western-Type Diet

Apoe^-/- and Ldlr^-/- mice are two animal models extensively used for atherosclerosis research. We previously reported that Apoe^-/- mice on certain genetic backgrounds, including C3H/HeJ (C3H), develop type 2 diabetes when fed a Western diet. We sought to characterize diabetes-related traits in C3H-Ldlr^-/- mice through comparing with C3H-Apoe^-/- mice. On a chow diet, Ldlr^-/- mice had lower plasma total and non-HDL cholesterol levels but higher HDL levels than Apoe^-/- mice. Fasting plasma glucose was much lower in Ldlr^-/- than Apoe^-/- mice (male: 122.5 ± 5.9 vs. 229.4 ± 17.5 mg/dL; female: 144.1 ± 12.4 vs. 232.7 ± 6.4 mg/dL). When fed a Western diet, Ldlr^-/- and Apoe^-/- mice developed severe hypercholesterolemia and also hyperglycemia with fasting plasma glucose levels exceeding 250 mg/dL. Both knockouts had similar non-HDL cholesterol and triglyceride levels, and their fasting glucose levels were also similar. Male Ldlr^-/- mice exhibited greater glucose tolerance and insulin sensitivity compared to their Apoe^-/- counterpart. Female mice showed similar glucose tolerance and insulin sensitivity though Ldlr^-/- mice had higher non-fasting glucose levels. Male Ldlr^-/- and Apoe^-/- mice developed moderate obesity on the Western diet, but female mice did not. These results indicate that the Western diet and ensuing hyperlipidemia lead to the development of type 2 diabetes, irrespective of underlying genetic causes.

Genetic Evidence for a Causal Relationship between Hyperlipidemia and Type 2 Diabetes in Mice

Dyslipidemia is considered a risk factor for type 2 diabetes (T2D), yet studies with statins and candidate genes suggest that circulating lipids may protect against T2D development. Apoe-null (Apoe^-/-) mouse strains develop spontaneous dyslipidemia and exhibit a wide variation in susceptibility to diet-induced T2D. We thus used Apoe^-/- mice to elucidate phenotypic and genetic relationships of circulating lipids with T2D. A male F2 cohort was generated from an intercross between LP/J and BALB/cJ Apoe^-/- mice and fed 12 weeks of a Western diet. Fasting, non-fasting plasma glucose, and lipid levels were measured and genotyping was performed using miniMUGA arrays. We uncovered a major QTL near 60 Mb on chromosome 15, Nhdlq18, which affected non-HDL cholesterol and triglyceride levels under both fasting and non-fasting states. This QTL was coincident with Bglu20, a QTL that modulates fasting and non-fasting glucose levels. The plasma levels of non-HDL cholesterol and triglycerides were closely correlated with the plasma glucose levels in F2 mice. Bglu20 disappeared after adjustment for non-HDL cholesterol or triglycerides. These results demonstrate a causative role for dyslipidemia in T2D development in mice.

Genetic Connection between Hyperglycemia and Carotid Atherosclerosis in Hyperlipidemic Mice

Type 2 diabetes (T2D) is a major risk for atherosclerosis and its complications. Apoe-null (Apoe^−/−) mouse strains exhibit a wide range of variations in susceptibility to T2D and carotid atherosclerosis, with the latter being a major cause of ischemic stroke. To identify genetic connections between T2D and carotid atherosclerosis, 145 male F2 mice were generated from LP/J and BALB/cJ Apoe^−/− mice and fed 12 weeks of a Western diet. Atherosclerotic lesions in the carotid arteries, fasting, and non-fasting plasma glucose levels were measured, and genotyping was performed using miniMUGA arrays. Two significant QTL (quantitative trait loci) on chromosomes (Chr) 6 and 15 were identified for carotid lesions. The Chr15 QTL coincided precisely with QTL Bglu20 for fasting and non-fasting glucose levels. Carotid lesion sizes showed a trend toward correlation with fasting and non-fasting glucose levels in F2 mice. The Chr15 QTL for carotid lesions was suppressed after excluding the influence from fasting or non-fasting glucose. Likely candidate genes for the causal association were Tnfrsf11b, Deptor, and Gsdmc2. These results demonstrate a causative role for hyperglycemia in the development of carotid atherosclerosis in hyperlipidemic mice.

Identification of Mep1a as a susceptibility gene for atherosclerosis in mice

Atherosclerosis is the underlying cause of heart attack, ischemic stroke and peripheral arterial disease, and genetic factors involved remain mostly unidentified. We previously identified a significant locus on mouse chromosome 17 for atherosclerosis, Ath49, in an intercross between BALB/c and SM strains. Ath49 partially overlaps in the confidence interval with Ath22 mapped in an AKR × DBA/2 intercross. Bioinformatics analysis prioritized Mep1a, encoding meprin 1α metalloendopeptidase, as a likely candidate gene for Ath49. To prove causality, Mep1a-/-Apoe-/- mice were generated and compared with Mep1a+/+Apoe-/- mice for atherosclerosis development. Mep1a was found abundantly expressed in atherosclerotic lesions but not in healthy aorta and liver of mice. Mep1a-/- Apoe-/- mice exhibited significant reductions in both early and advanced lesion sizes. Loss of Mep1a led to decreased necrosis but increased macrophage and neutrophil contents in advanced lesions, reduced plasma levels of CXCL5 and an oxidative stress biomarker. In addition, Mep1a-/- mice had significantly reduced triglyceride levels on a chow diet. Thus, Mep1a is a susceptibility gene for atherosclerosis and aggravates atherosclerosis partially through action on oxidative stress and inflammation.