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Interaction Between Type 2 Diabetes Prevention Strategies and Genetic Determinants of Coronary Artery Disease on Cardiometabolic Risk Factors.
Merino, J, Jablonski, KA, Mercader, JM, Kahn, SE, Chen, L, Harden, M, Delahanty, LM, Araneta, MRG, Walford, GA, Jacobs, SBR, et al
Diabetes. 2020;69(1):112-120
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Plain language summary
Individual risk of Coronary Artery Disease (CAD) and type 2 diabetes reflects the interplay between lifestyle behaviours acting on a backdrop of genetic predisposition. The aim of this study was to examine whether type 2 diabetes prevention strategies, either an intensive lifestyle intervention (ILS) or metformin treatment (MET), modify the association between CAD genetic risk and cardiometabolic risk factors (CRFs) in participants at high risk of type 2 diabetes. The study is a randomised controlled trial were participants were randomly allocated to one of the three groups; ILS (n = 1,079), MET (850 mg twice daily [n = 1,073]), or placebo (n = 1,082). Results indicate that there weren’t major significant differences in baseline characteristics, except for lower high-density lipoprotein and higher triglyceride in the placebo individuals compared with individuals assigned to MET or ILS. In fact, either an ILS or MET has a beneficial effect on 1-year change in different CRFs. Authors conclude that type 2 diabetes–preventive strategies for individuals at high risk of type 2 diabetes provide beneficial effects on CRFs regardless of CAD genetic risk profile.
Abstract
Coronary artery disease (CAD) is more frequent among individuals with dysglycemia. Preventive interventions for diabetes can improve cardiometabolic risk factors (CRFs), but it is unclear whether the benefits on CRFs are similar for individuals at different genetic risk for CAD. We built a 201-variant polygenic risk score (PRS) for CAD and tested for interaction with diabetes prevention strategies on 1-year changes in CRFs in 2,658 Diabetes Prevention Program (DPP) participants. We also examined whether separate lifestyle behaviors interact with PRS and affect changes in CRFs in each intervention group. Participants in both the lifestyle and metformin interventions had greater improvement in the majority of recognized CRFs compared with placebo (P < 0.001) irrespective of CAD genetic risk (P interaction > 0.05). We detected nominal significant interactions between PRS and dietary quality and physical activity on 1-year change in BMI, fasting glucose, triglycerides, and HDL cholesterol in individuals randomized to metformin or placebo, but none of them achieved the multiple-testing correction for significance. This study confirms that diabetes preventive interventions improve CRFs regardless of CAD genetic risk and delivers hypothesis-generating data on the varying benefit of increasing physical activity and improving diet on intermediate cardiovascular risk factors depending on individual CAD genetic risk profile.
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In a randomized trial in prostate cancer patients, dietary protein restriction modifies markers of leptin and insulin signaling in plasma extracellular vesicles.
Eitan, E, Tosti, V, Suire, CN, Cava, E, Berkowitz, S, Bertozzi, B, Raefsky, SM, Veronese, N, Spangler, R, Spelta, F, et al
Aging cell. 2017;16(6):1430-1433
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Obesity and insulin resistance are associated with accelerated aging and increased risk of many age-related diseases. The risk of many cancers, including prostate cancer, increases with age and being overweight further increases the risk. The aim of the study is to investigate the inhibition of tumour growth through the effect of protein restriction diets and hence, levels of circulating amino acids. The participants of the study were men (n=38) with prostate cancer awaiting prostatectomy surgery. Most of the subjects were overweight with a BMI of 30.45 ± 5.8. They were randomly assigned to either a control diet or a protein restricted diet. In comparison to the control diet, results show that protein restriction increased the levels of receptors (a protein molecule that receives chemical signals from outside a cell) responsible of leptin, the hormone that controls hunger. The results also show that protein restriction can improve the body’s sensitivity to the effects of the insulin in neurons (a nerve cell specialised to transmit information throughout the body). Authors conclude that protein restriction can counteract major age-related diseases.
Abstract
Obesity, metabolic syndrome, and hyperleptinemia are associated with aging and age-associated diseases including prostate cancer. One experimental approach to inhibit tumor growth is to reduce dietary protein intake and hence levels of circulating amino acids. Dietary protein restriction (PR) increases insulin sensitivity and suppresses prostate cancer cell tumor growth in animal models, providing a rationale for clinical trials. We sought to demonstrate that biomarkers derived from plasma extracellular vesicles (EVs) reflect systemic leptin and insulin signaling and respond to dietary interventions. We studied plasma samples from men with prostate cancer awaiting prostatectomy who participated in a randomized trial of one month of PR or control diet. We found increased levels of leptin receptor in the PR group in total plasma EVs and in a subpopulation of plasma EVs expressing the neuronal marker L1CAM. Protein restriction also shifted the phosphorylation status of the insulin receptor signal transducer protein IRS1 in L1CAM+ EVs in a manner suggestive of improved insulin sensitivity. Dietary PR modifies indicators of leptin and insulin signaling in circulating EVs. These findings are consistent with improved insulin and leptin sensitivity in response to PR and open a new window for following physiologic responses to dietary interventions in humans.