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Alterations of gut microbiota are associated with blood pressure: a cross-sectional clinical trial in Northwestern China.
Lv, J, Wang, J, Yu, Y, Zhao, M, Yang, W, Liu, J, Zhao, Y, Yang, Y, Wang, G, Guo, L, et al
Journal of translational medicine. 2023;21(1):429
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Hypertension (HTN) is a complex and modifiable risk factor for cardiovascular diseases (CVDs) and stroke, while a diverse range of endogenous and environmental factors contribute to both HTN onset and progression. The adult gut microbiota (GM) consists of trillions of microorganisms and maintains the gut immunity and whole-body homeostasis. The aim of this study was to investigate the GM characteristics in HTN subjects in Northwestern China, and evaluate the associations of GM with blood pressure levels based on sex differences. This study was a cross-sectional study. Participants were randomly selected for the HTN and control groups. A total of 36 HTN subjects (24 females and 12 males) and 18 controls (9 females and 9 males) were randomly selected for metagenomic analysis. Results showed a positive association between GM characteristics and alterations and HTN in both females and males. Thus, GM dysbiosis underlies HTN pathogenesis. Authors conclude that further studies are needed to elucidate the underlying mechanisms and potential therapeutic interventions targeting GM for HTN prevention and management
Abstract
BACKGROUND The human gut microbiota (GM) is involved in the pathogenesis of hypertension (HTN), and could be affected by various factors, including sex and geography. However, available data directly linking GM to HTN based on sex differences are limited. METHODS This study investigated the GM characteristics in HTN subjects in Northwestern China, and evaluate the associations of GM with blood pressure levels based on sex differences. A total of 87 HTN subjects and 45 controls were recruited with demographic and clinical characteristics documented. Fecal samples were collected for 16S rRNA gene sequencing and metagenomic sequencing. RESULTS GM diversity was observed higher in females compared to males, and principal coordinate analysis showed an obvious segregation of females and males. Four predominant phyla of fecal GM included Firmicutes, Bacteroidetes, Actinobacteria and Proteobacteria. LEfSe analysis indicated that phylum unidentified_Bacteria was enriched in HTN females, while Leuconostocaceae, Weissella and Weissella_cibaria were enriched in control females (P < 0.05). Functionally, ROC analysis revealed that Cellular Processes (0.796, 95% CI 0.620 ~ 0.916), Human Diseases (0.773, 95% CI 0.595 ~ 0.900), Signal transduction (0.806, 95% CI 0.631 ~ 0.922) and Two-component system (0.806, 95% CI 0.631 ~ 0.922) could differentiate HTN females as effective functional classifiers, which were also positively correlated with systolic blood pressure levels. CONCLUSIONS This work provides evidence of fecal GM characteristics in HTN females and males in a northwestern Chinese population, further supporting the notion that GM dysbiosis may participate in the pathogenesis of HTN, and the role of sex differences should be considered. Trial registration Chinese Clinical Trial Registry, ChiCTR1800019191. Registered 30 October 2018 - Retrospectively registered, http://www.chictr.org.cn/ .
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Comparison of dietary macronutrient patterns of 14 popular named dietary programmes for weight and cardiovascular risk factor reduction in adults: systematic review and network meta-analysis of randomised trials.
Ge, L, Sadeghirad, B, Ball, GDC, da Costa, BR, Hitchcock, CL, Svendrovski, A, Kiflen, R, Quadri, K, Kwon, HY, Karamouzian, M, et al
BMJ (Clinical research ed.). 2020;369:m696
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Dietary recommendations to combat obesity and its associated risk for heart disease are extensive. Many different diets and patterns of eating are being tried by millions of people, however no systematic review comparing their effectiveness has been performed. This systematic review and meta-analysis aimed to determine the effectiveness of 14 popular diets and diets which restrict certain nutrients on weight loss and heart disease risk. The results identified 121 studies with 21942 patients for inclusion. The Atkins diet, the Zone diet and the Dietary Approaches to Stop Hypertension (DASH) diet were the most effective for weight loss and for reducing blood pressure. Low carbohydrate and low-fat diets achieved similar weight loss when compared to a normal diet. Low carbohydrate diets had less effect on heart disease risk factors than low fat and moderate macronutrient diets. There were no improvements in good cholesterol with any of the diets. Interestingly any benefits on weight loss for any of the diets disappeared after 12 months and this was also observed for heart disease risk, except in those on the Mediterranean diet. It was concluded that most diets show improvements to weight loss and heart disease risk factors over 6 months, however these are largely unsustainable after 12 months. Differences between diets are small and healthcare practitioners could use this study to recommend any number of diets to achieve weight loss and the Mediterranean diet in particular to decrease heart disease risk. However, it is important to understand that this may be a short-term fix and at 12 months patients need to be assessed to ensure that weight loss is sustained.
Abstract
OBJECTIVE To determine the relative effectiveness of dietary macronutrient patterns and popular named diet programmes for weight loss and cardiovascular risk factor improvement among adults who are overweight or obese. DESIGN Systematic review and network meta-analysis of randomised trials. DATA SOURCES Medline, Embase, CINAHL, AMED, and CENTRAL from database inception until September 2018, reference lists of eligible trials, and related reviews. STUDY SELECTION Randomised trials that enrolled adults (≥18 years) who were overweight (body mass index 25-29) or obese (≥30) to a popular named diet or an alternative diet. OUTCOMES AND MEASURES Change in body weight, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, systolic blood pressure, diastolic blood pressure, and C reactive protein at the six and 12 month follow-up. REVIEW METHODS Two reviewers independently extracted data on study participants, interventions, and outcomes and assessed risk of bias, and the certainty of evidence using the GRADE (grading of recommendations, assessment, development, and evaluation) approach. A bayesian framework informed a series of random effects network meta-analyses to estimate the relative effectiveness of the diets. RESULTS 121 eligible trials with 21 942 patients were included and reported on 14 named diets and three control diets. Compared with usual diet, low carbohydrate and low fat diets had a similar effect at six months on weight loss (4.63 v 4.37 kg, both moderate certainty) and reduction in systolic blood pressure (5.14 mm Hg, moderate certainty v 5.05 mm Hg, low certainty) and diastolic blood pressure (3.21 v 2.85 mm Hg, both low certainty). Moderate macronutrient diets resulted in slightly less weight loss and blood pressure reductions. Low carbohydrate diets had less effect than low fat diets and moderate macronutrient diets on reduction in LDL cholesterol (1.01 mg/dL, low certainty v 7.08 mg/dL, moderate certainty v 5.22 mg/dL, moderate certainty, respectively) but an increase in HDL cholesterol (2.31 mg/dL, low certainty), whereas low fat (-1.88 mg/dL, moderate certainty) and moderate macronutrient (-0.89 mg/dL, moderate certainty) did not. Among popular named diets, those with the largest effect on weight reduction and blood pressure in comparison with usual diet were Atkins (weight 5.5 kg, systolic blood pressure 5.1 mm Hg, diastolic blood pressure 3.3 mm Hg), DASH (3.6 kg, 4.7 mm Hg, 2.9 mm Hg, respectively), and Zone (4.1 kg, 3.5 mm Hg, 2.3 mm Hg, respectively) at six months (all moderate certainty). No diets significantly improved levels of HDL cholesterol or C reactive protein at six months. Overall, weight loss diminished at 12 months among all macronutrient patterns and popular named diets, while the benefits for cardiovascular risk factors of all interventions, except the Mediterranean diet, essentially disappeared. CONCLUSIONS Moderate certainty evidence shows that most macronutrient diets, over six months, result in modest weight loss and substantial improvements in cardiovascular risk factors, particularly blood pressure. At 12 months the effects on weight reduction and improvements in cardiovascular risk factors largely disappear. SYSTEMATIC REVIEW REGISTRATION PROSPERO CRD42015027929.
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Testosterone Deficiency, Weakness, and Multimorbidity in Men.
Peterson, MD, Belakovskiy, A, McGrath, R, Yarrow, JF
Scientific reports. 2018;8(1):5897
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With age, the occurrence of total testosterone (TT) deficiency in men also increases. Such deficiency can have a detrimental impact on the musculoskeletal system leading to bone and muscle loss, increasing the risk of cardiovascular disease and all-cause mortality. Hence muscle weakness is a known a predicitve factor for chronic disease. Whereby reference ranges have been set for testosterone levels in young healthy men, uncertainty exists about optimal levels throughout different age ranges, ethnicities and in concurrence with diseases. This observational study evaluated how TT deficiency and muscle weakness assessed via grip strength, relates to chronic health conditions in men. The study included 2399 young, middle-aged, and older men in the US, with a diverse ethnic backgrounds, who presented with and without testosterone deficiency. The findings indicated that TT levels were highest amongst young men, yet no particular difference was seen in levels between middle-aged and older men. Grip strength decreased in the higher age categories. Chronic health conditions were more common in young and older men who displayed testosterone deficiencies, whilst low testosterone and reduced grip strength were linked to the presence of chronic disease in all age groups. Overall the study confirmed previous research, that in men with testosterone deficiency chronic disease was much more prevalent, even after accounting for other variables. The study also observed a much lower average of TT levels in young men compared to previous research, in mostly white males. Thus testosterone deficiency appears much more common in men of all ages when including a variety of ethnic groups. As low testosterone may play an early, causal role in the chronic disease process, continuous monitoring of testosterone levels through the life span may aid the early identification of chronic disease development or disease progression. Further research is needed on the independent and joint effects of low TT and muscular weakness. From a clinical perspective, this study affirms that low testosterone in men is a presenting risk factor for chronic disease and that chronic disease is commonly accompanied by low testosterone. It also highlights some unsettled aspects around reference ranges of testosterone
Abstract
The purposes of this study were to evaluate the association between total testosterone (TT) deficiency and weakness on multimorbidity in men. Analyses were performed to examine the prevalence of multimobidity among young, middle-aged, and older men, with and without testosterone deficiency. Multivariate logistic models were also used to determine the association between age-specific TT tertiles and multimorbidity, adjusting for key sociodemographic variables, as well as a secondary analysis adjusted for grip strength. Multimorbidity was more prevalent among men with testosterone deficiency, compared to normal TT in the entire group (36.6% vs 55.2%; p < 0.001); however, differences were only seen within young (testosterone deficiency: 36.4%; normal TT: 13.5%; p < 0.001) and older men (testosterone deficiency: 75.0%; normal TT: 61.5%; p < 0.001). Robust associations were found between the age-specific low-TT (OR: 2.87; 95%CI: 2.14-3.83) and moderate-TT (OR: 1.67; 95%CI: 1.27-2.20) tertiles (reference high-TT) and multimorbidity. Secondary analysis demonstrated that both low TT (OR: 1.82; 95%CI: 1.29-2.55) and moderate-TT (OR: 1.31; 95%CI: 1.01-1.69) were associated with multimorbidity, even after adjusting for obesity (OR: 1.75; 95%CI: 1.07-2.87) and NGS (OR: 1.21 per 0.05 unit lower NGS). Low TT and weakness in men were independently associated with multimorbidity at all ages; however, multimorbidity was more prevalent among young and older men with testosterone deficiency.