Relationships of plasma lipoprotein(a) levels with insulin resistance in hypertensive patients

Background

Lipoprotein(a) [Lp(a)] is an emergent cardiovascular risk factor that is related to the presence and severity of cardiovascular damage in hypertensive patients. In these patients, insulin resistance is frequently detected but its relationship with plasma Lp(a) is not clear. The aim of this study was to examine the relationships between Lp(a) and variables of glucose metabolism in hypertension.

Methods

In 527 consecutive, non-diabetic, middle-aged hypertensive patients we measured anthropometric indexes, 24-hour creatinine clearance, lipid profile including Lp(a) levels, fasting glucose, insulin and C-peptide, and calculated the Homeostatic Model Assessment (HOMA) index.

Results

Lp(a) levels were significantly and progressively lower with increasing HOMA-index values. Lp(a) was inversely related to fasting glucose, insulin, and C-peptide, HOMA-index, and creatinine clearance and directly related to LDL-cholesterol. Multiple regression analysis adjusted for age, sex, body mass index, blood pressure, smoking habit, alcohol intake, renal function, lipid profile, history of cardiovascular events, and drug use showed that HOMA-index and creatinine clearance were inversely and independently associated to Lp(a) levels.

Conclusions

Insulin resistance and higher fasting insulin levels are associated with lower plasma Lp(a) in hypertensive patients. This association might be relevant in the assessment of cardiovascular risk in these patients.     

Walnut-enriched diet reduces fasting non-HDL-cholesterol and apolipoprotein B in healthy Caucasian subjects: A randomized controlled cross-over clinical trial

Background

Walnut consumption is associated with reduced risk of coronary heart disease (CHD).

Objective

We assessed the effect of walnuts on lipid and glucose metabolism, adipokines, inflammation and endothelial function in healthy Caucasian men and postmenopausal women ≥ 50 years old.

Design

Forty subjects (mean ± SEM: age 60 ± 1 years, BMI 24.9 ± 0.6 kg/m²; 30 females) were included in a controlled, cross-over study and randomized to receive first a walnut-enriched (43 g/d) and then a Western-type (control) diet or vice-versa, with each lasting 8 weeks and separated by a 2-week wash-out. At the beginning and end of each diet phase, measurements of fasting values, a mixed meal test and an assessment of postprandial endothelial function (determination of microcirculation by peripheral artery tonometry) were conducted. Area under the curve (AUC), incremental AUC (iAUC) and treatment × time interaction (shape of the curve) were evaluated for postprandial triglycerides, VLDL-triglycerides, chylomicron-triglycerides, glucose and insulin.

Results

Compared with the control diet, the walnut diet significantly reduced non-HDL-cholesterol (walnut vs. control: − 10 ± 3 vs. − 3 ± 2 mg/dL; p = 0.025) and apolipoprotein-B (− 5.0 ± 1.3 vs. − 0.2 ± 1.1 mg/dL; p = 0.009) after adjusting for age, gender, BMI and diet sequence. Total cholesterol showed a trend toward reduction (p = 0.073). Fasting VLDL-cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides and glucose, insulin, HOMA-IR, and HbA1c did not change significantly. Similarly, fasting adipokines, C-reactive protein, biomarkers of endothelial dysfunction, postprandial lipid and glucose metabolism and endothelial function were unaffected.

Conclusion

Daily consumption of 43 g of walnuts for 8 weeks significantly reduced non-HDL-cholesterol and apolipoprotein-B, which may explain in part the epidemiological observation that regular walnut consumption decreases CHD risk.     

Weight gain prevention buffers the impact of CETP rs3764261 on high density lipoprotein cholesterol in young adulthood: The Study of Novel Approaches to Weight Gain Prevention (SNAP)

Background and Aims

Two weight gain prevention strategies, one targeting small changes to diet and physical activity and a second targeting large changes, significantly reduced weight gain in young adulthood. We examined whether weight gain prevention blunts genetic risk for body weight increase and/or high density lipoprotein cholesterol (HDL-C) lowering over two years.

The effects of the Dietary Approaches to Stop Hypertension (DASH) diet on metabolic risk factors in patients with chronic disease: A systematic review and meta-analysis of randomized controlled trials

AimsThe DASH diet was designed for helping control of blood pressure but, fortunately, it can also be prescribed for many other chronic conditions. The current study intended to assess the potential effects of DASH diet on metabolic risk factors in patients with chronic disease.Data synthesisWe carried out a systematic literature search for RCTs from inception until July 2020. A total of 54 clinical trials were included in the final analysis. Compared to control groups, a significant lower effect of the DASH diet was noted for body weight (−1.59 kg; p < 0.001), BMI (−0.64 kg/m²; p < 0.001), and WC (−1.93 cm; p < 0.001) as well as for SBP (−3.94 mmHg; p < 0.001) and DBP (−2.44 mmHg; P < 0.001). The DASH diet significantly decreased TC (−5.12 mg/dl; p = 0.008) and LDL-C levels (−3.53 mg/dl; p = 0.041), but not HDL-C (0.30 mg/dl; p = 0.510), TG (−4.22 mg/dl; p = 0.067), and VLDL-C (−2.16 mg/dl; p = 0.062). No significant effect of the DASH diet was noted for blood glucose (−0.38 mg/dl; p = 0.216), insulin (−0.03 μIU/mL; p = 0.817), HOMA-IR (−0.15; p = 0.132), and CRP (−0.33 mg/l; p = 0.173).ConclusionsThe DASH diet is a feasible approach to weight loss and to control blood pressure and hypercholesterolemia.     

Sustained improvements in the cardiometabolic profile of patients with obstructive sleep apnea after a weight-loss Mediterranean diet/lifestyle intervention: 12-month follow-up (6 months post-intervention) of the “MIMOSA” randomized clinical trial

Background and aimsObstructive sleep apnea (OSA) and the metabolic syndrome (MS) frequently coexist and lead to increased cardiometabolic morbidity. We aimed to explore the long-term cardiometabolic benefits of a weight-loss Mediterranean diet/lifestyle intervention in OSA.Methods and resultsAs many as 180 adults with overweight/obesity and polysomnography-diagnosed moderate-to-severe OSA were randomized to a standard care (SCG, n = 62), a Mediterranean diet (MDG, n = 59) or a Mediterranean lifestyle group (MLG, n = 59). All groups were prescribed with continuous positive airway pressure (CPAP), while intervention arms (MDG/MLG) additionally participated in a 6-month weight-loss intervention based on the Mediterranean diet/lifestyle. Cardiometabolic parameters were evaluated at baseline and 12 months (6 months post-intervention). Data were analyzed using the intention-to-treat method, and 12-month between-group differences were explored while adjusting for age, sex, baseline status and CPAP use. Compared to the SCG, intervention arms exhibited lower insulin, triglycerides and high-sensitivity C-reactive protein, and higher high-density lipoprotein cholesterol; the MDG also exhibited lower diastolic blood pressure, while the MLG exhibited lower glucose and systolic blood pressure (all P < 0.050). The relative risk (95% confidence interval) of MS was 0.60 (0.36, 0.99) in the MDG versus the SCG, 0.33 (0.20, 0.55) in the MLG versus the SCG and 0.55 (0.32, 0.93) in the MLG versus the MDG. The risk of MS remained lower in the MLG versus the other study groups (both P < 0.050) after additional adjustment for body weight change.ConclusionCardiometabolic benefits of a 6-month healthy dietary/lifestyle intervention are sustainable 6 months post-intervention in OSA.Trial registrationClinicalTrials.gov, NCT02515357, August 4, 2015.     

Genetic factors in sleep-disordered breathing

Sleep-disordered breathing (SDB) is characterized by repetitive episodes of decreased or arrested respiratory airflow during sleep. SDB is common and affects approximately 20% of the Japanese general population. Most traits of normal sleep and SDB show familial aggregation, suggesting significant effects of genetic factors. Obstructive sleep apnea (OSA) is the most common type of SDB and has a high heritability. Regardless of high heritability, no risk locus for OSA has reached a genome-wide level of significance (P < 5×10^?8) in linkage or candidate gene analysis. However, a recent genome-wide association study identified some genetic risks for OSA with P < 5×10^?8 for the first time. The identified genes are associated with inflammation, hypoxia signaling, and sleep pathways. The effects of genetic factors on the consequences of OSA has not been determined, although a correlation between OSA and cardiovascular disease may differ across races. Congenital central hypoventilation syndrome (CCHS) is a genetically inherited disorder caused by mutations in the paired-like homeobox 2B (PHOX2B) gene of polyalanine repeat mutations in the 20-alanine repeat or non-polyalanine repeat mutations. PHOX2B genotypes are also associated with clinical phenotypes of CCHS, including severity of hypoventilation. SDB, including obesity hypoventilation syndrome, is often seen in genetic obesity-associated disorders such as Prader-Willi syndrome. Although advances in genetics have resulted in identification of some genetic causes of SDB, further studies are required to elucidate the cellular and molecular mechanisms between genetic risks and clinical manifestations.