Lipoprotein lipase activity does not predict very low-density lipoprotein-triglyceride fatty acid oxidation during exercise

Discordance between Remnant Cholesterol and Low-density Lipoprotein Cholesterol Predicts Cardiovascular Disease: the Kailuan Prospective Cohort Study

BACKGROUND

Previous studies have shown that remnant cholesterol (RC) was associated with cardiovascular disease (CVD). The study aim to identify the association of RC and the discordance between RC and lipoprotein cholesterol (LDL-C) with CVD.

METHODS

Data was obtained from the Kailuan study. RC was calculated as the non high-density lipoprotein cholesterol minus LDL-C. Discordant RC and LDL-C were defined by percentile difference and clinical cutoff points. Cox proportional hazard models were used to explore the association of RC and the discordance between RC and LDL-C with CVD.

RESULTS

Total of 96,769 participants were inclued, with the median age of 51.61 years, 79.56% of male. There was a significant association between RC levels and the risk of CVD, with an HR of 1.10 (95% CI, 1.08-1.13) in the continuous analysis. The discordantly high RC group had a significant increase in CVD, MI, and stroke risk, with HRs of 1.18 (95%CI, 1.10-1.26), 1.23 (1.06-1.43), and 1.15 (1.07-1.24), respectively. Compared to the group with low LDL-C and low RC, the group with low LDL-C and high RC had significantly higher incidences of CVD (HR, 1.33 [95% CI, 1.26-1.40]), MI (HR, 1.59 [95% CI, 1.41-1.80]), and stroke (HR, 1.28 [95% CI, 1.20-1.35]).

CONCLUSIONS

Elevated levels of RC and discordantly high RC with LDL-C both were associated with the risk of CVD, MI, and stroke. These findings demonstrate the clinical significance of identifying residual risk related to RC.

Cumulative remnant cholesterol burden increases the risk of cardiovascular disease among young adults

BACKGROUND

Previous studies have shown that remnant cholesterol (RC) was associated with cardiovascular disease (CVD) among middle-aged or older adults. However, lack of evidence on long-term exposures to RC and their role in CVD risk among young adults. We thus aimed to explore the association between cumulative RC burden and CVD in young adults.

METHODS

We enrolled participants younger than 45 years free of CVD history in the Kailuan Study who completed the first three health examinations from 2006 to 2010. Cumulative RC burden included cumulative RC burden score, time-weighted cumulative RC, exposure duration of high RC, and time course of RC accumulation. The outcome was the incidence of CVD. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) between cumulative RC burden and CVD risk.

RESULTS

A total of 15,219 participants were included (73.70% male, median age 39.13 years). During a median follow-up duration of 8.71 years (interquartile range: 8.4-9.15 years), 502 individuals developed CVD. After adjustment for traditional cardiovascular risk factors, highest risk of CVD was observed in participants with the highest cumulative RC burden score (HR, 1.66; 95% CI, 1.29-2.12), the highest quartile time-weighted cumulative RC (HR,1.50; 95% CI, 1.15-1.96), the longest exposure duration of high RC (HR, 1.71; 95% CI, 1.21-2.42), and those with cumulative RC burden and positive slope (HR, 1.79; 95% CI, 1.35-2.36).

CONCLUSIONS

Cumulative RC burden increased the risk of CVD among young adults, suggesting that maintaining low RC levels throughout young adulthood may minimize CVD risk.

KEY LEARNING POINTS

The Impact of Exercise on Immunity, Metabolism, and Atherosclerosis

Physical exercise represents an effective preventive and therapeutic strategy beneficially modifying the course of multiple diseases. The protective mechanisms of exercise are manifold; primarily, they are elicited by alterations in metabolic and inflammatory pathways. Exercise intensity and duration strongly influence the provoked response. This narrative review aims to provide comprehensive up-to-date insights into the beneficial effects of physical exercise by illustrating the impact of moderate and vigorous exercise on innate and adaptive immunity. Specifically, we describe qualitative and quantitative changes in different leukocyte subsets while distinguishing between acute and chronic exercise effects. Further, we elaborate on how exercise modifies the progression of atherosclerosis, the leading cause of death worldwide, representing a prime example of a disease triggered by metabolic and inflammatory pathways. Here, we describe how exercise counteracts causal contributors and thereby improves outcomes. In addition, we identify gaps that still need to be addressed in the future.

Effects of SGLT2 inhibition on lipid transport in adipose tissue in type 2 diabetes

SGLT2 inhibition induces an insulin-independent reduction in plasma glucose causing increased lipolysis and subsequent lipid oxidation by energy-consuming tissues. However, it is unknown whether SGLT2 inhibition also affects lipid storage in adipose tissue. Therefore, we aimed to determine the effects of SGLT2 inhibition on lipid storage and lipolysis in adipose tissue. We performed a randomized, double-blinded, placebo-controlled crossover design of 4 weeks of empagliflozin 25 mg and placebo once-daily in 13 individuals with type 2 diabetes treated with metformin. Adipose tissue fatty acid uptake, lipolysis rate and clearance were measured by 11C-palmitate PET/CT. Adipose tissue glucose uptake was measured by 18F-FDG PET/CT. Protein and gene expression of pathways involved in lipid storage and lipolysis were measured in biopsies of abdominal s.c. adipose tissue. Subjects were weight stable, which allowed us to quantify the weight loss-independent effects of SGLT2 inhibition. We found that SGLT2 inhibition did not affect free fatty acids (FFA) uptake in abdominal s.c. adipose tissue but increased FFA uptake in visceral adipose tissue by 27% (P < 0.05). In addition, SGLT2 inhibition reduced GLUT4 protein (P = 0.03) and mRNA content (P = 0.01) in abdominal s.c. adipose tissue but without affecting glucose uptake. In addition, SGLT2 inhibition decreased the expression of genes involved in insulin signaling in adipose tissue. We conclude that SGLT2 inhibition reduces GLUT4 gene and protein expression in abdominal s.c. adipose tissue, which could indicate a rebalancing of substrate utilization away from glucose oxidation and lipid storage capacity through reduced glycerol formation.

Effects of statin therapy and exercise on postprandial triglycerides in overweight individuals with hypercholesterolaemia

AIMS

To determine the effects of statins on postprandial lipaemia (PPL) and to study if exercise could enhance statin actions.

METHODS

Ten hypercholesteraemic (blood cholesterol 204 ± 36 mg dL^-1 ; low-density lipoprotein-cholesterol 129 ± 32 36 mg dL^-1 ) overweight (body mass index 30 ± 4 kg m^-2 ), metabolic syndrome individuals chronically medicated with statins (>6 months) underwent 5-hour PPL tests in 4 occasions in a randomized order: (i) substituting their habitual statin medication by placebo for 96 hours (PLAC trial); (ii) taking their habitual statin medicine (STA trial); (iii) placebo combined with a bout of intense aerobic exercise (EXER+PLAC trial); and (iv) combining exercise and statin medicine (EXER+STA trial).

RESULTS

Before the fat meal, statin withdrawal (i.e. PLAC and EXER+PLAC) increased blood triglycerides (TG; 24%), low-density lipoprotein-cholesterol (31%) and total cholesterol (19%; all P < .05) evidencing treatment compliance. After the meal, statin withdrawal increased 5-hour postprandial TG (PPTG) compared to its matched trials (94% higher PLAC vs STA and 45% higher EXER+PLAC vs EXER+STA; P < .05). EXER+PLAC trial did not lower PPTG below PLAC (i.e. incremental AUC of 609 ± 152 vs 826 ± 190 mg dL^-1 5 h; P = .09). Adding exercise to statin did not result in larger reductions in PPTG (i.e. EXER+STA vs STA incremental area under the curve of 421 ± 87 vs 421 ± 84 mg dL^-1 5 h; P = .99).

CONCLUSION

In hypercholesteraemic metabolic syndrome individuals, chronic statin therapy blunts the elevations in TG after a fat meal (i.e. incremental area under the curve of PPTG) reducing the cardiovascular risk associated to their atherogenic dyslipidaemia. However, a single bout of intense aerobic exercise before the high fat meal, does not reduce PPTG but also does not interfere with the effects of statin treatment.

Effects of short-term exercise on food intake and the expression of appetite-regulating factors in goldfish

In mammals, growing evidence indicates that exercise affects food intake, metabolism and the expression and blood levels of appetite regulators. In this study, we examined the effects of short-term (30 min, at low and high water flow) exercise on food intake, glucose levels and the expressions of appetite regulators in goldfish hypothalamus (irisin, orexin, CART, leptin), intestine (CCK, PYY, proglucagon/GLP-1), muscle (irisin) and liver (leptin), of brain-derived neurotrophic factor (BDNF) in brain, interleukin-6 (IL6) in muscle and hypothalamus, and major metabolic enzymes, the glycolytic enzyme glucokinase (GCK) and its regulatory protein (GCKR) in liver, the lipolytic enzyme lipoprotein lipase in intestine and muscle, and trypsin in intestine. Fish submitted to high flow exercise had a lower post-exercise food intake compared to control fish but no differences were seen in glucose levels between groups. Exercise induced an increase in hypothalamic expression levels of CART, IL6 and BDNF, but not orexin, irisin, CRF, leptin and NPY. High flow exercise induced an increase in intestine CCK, PYY and GLP-1, and muscle irisin and IL-6 expression levels. Exercise had no effects on expression levels of hepatic leptin or any of the metabolic enzymes examined. Our results suggest that, in goldfish, short-term exercise might decrease feeding in part by affecting the expressions of myokines and peripheral, but not central appetite regulators or metabolic enzyme/hormones.

VLDL triglyceride accumulation in skeletal muscle and adipose tissue in type 2 diabetes

PURPOSE OF REVIEW

Insulin resistance is closely linked to accumulation of lipid outside adipose tissue (ectopic fat storage). VLDL particles transport lipids from the liver to peripheral tissues. However, whether abnormalities in VLDL-triglyceride storage in muscle and adipose tissue exist in type 2 diabetes has previously been unknown, primarily because of methodological difficulties. Here, we review recent research on VLDL-triglyceride storage.

RECENT FINDINGS

In a recent study, men with type 2 diabetes had increased skeletal muscle VLDL-triglyceride storage compared to weight-matched nondiabetic men, potentially leading to intramyocellular triglyceride accumulation. In contrast, studies of adipose tissue VLDL-triglyceride storage have shown similar storage capacity in men with and without diabetes, both in the postabsorptive and the postprandial period. In the initial submission, studies have failed to show associations between lipoprotein lipase activity, considered the rate-limiting step in storage of lipids from lipoproteins, and VLDL-TG storage in both muscle and adipose tissue.

SUMMARY

Differences in muscle VLDL-triglyceride storage may lead to ectopic fat storage and contribute to the development of type 2 diabetes, whereas the ability to store VLDL-triglyceride in adipose tissue is preserved in type 2 diabetes.