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Nutrition, Metabolism, and... May 2021To systematically evaluate the evidence regarding the effects of foods on LDL cholesterol levels and to compare the findings with current guidelines. (Meta-Analysis)
Meta-Analysis
AIMS
To systematically evaluate the evidence regarding the effects of foods on LDL cholesterol levels and to compare the findings with current guidelines.
DATA SYNTHESIS
From inception through June 2019, we searched PubMed, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials for guidelines, systematic reviews, and RCTs (for coffee intake only) of at least 13 days duration. Additionally, we searched Trip database for guidelines from 2009 through Oct 2019. Language was restricted to English. The strength of evidence was evaluated using The Grading of Recommendations Assessment, Development, and Evaluation (GRADE). A total of 37 guidelines, 108 systematic reviews, and 20 RCTs were included. With high evidence, foods high in unsaturated and low in saturated and trans fatty acids (e.g. rapeseed/canola oil), with added plant sterols/stanols, and high in soluble fiber (e.g. oats, barley, and psyllium) caused at least moderate (i.e. 0.20-0.40 mmol/L) reductions in LDL cholesterol. Unfiltered coffee caused a moderate to large increase. Soy protein, tomatoes, flaxseeds, and almonds caused small reductions. With moderate evidence, avocados and turmeric caused moderate to large reductions. Pulses, hazelnuts, walnuts, high-fiber/wholegrain foods, and green tea caused small to moderate reductions, whereas sugar caused a small increase. Other identified foods were either neutral or had low or very low evidence regarding their effects.
CONCLUSIONS
Several foods distinctly modify LDL cholesterol levels. The results may aid future guidelines and dietary advice for hypercholesterolemia.
Topics: Adult; Biomarkers; Cholesterol, LDL; Diet; Diet, Healthy; Down-Regulation; Female; Humans; Hypercholesterolemia; Male; Middle Aged; Nutritive Value; Randomized Controlled Trials as Topic; Risk Assessment; Risk Factors; Risk Reduction Behavior; Treatment Outcome; Young Adult
PubMed: 33762150
DOI: 10.1016/j.numecd.2020.12.032 -
BMJ (Clinical Research Ed.) Apr 2020To determine the relative effectiveness of dietary macronutrient patterns and popular named diet programmes for weight loss and cardiovascular risk factor improvement... (Meta-Analysis)
Meta-Analysis
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.
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 4.37 kg, both moderate certainty) and reduction in systolic blood pressure (5.14 mm Hg, moderate certainty 5.05 mm Hg, low certainty) and diastolic blood pressure (3.21 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 7.08 mg/dL, moderate certainty 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.
Topics: Blood Pressure; Body Mass Index; Body Weight; Cardiovascular Diseases; Cholesterol, HDL; Cholesterol, LDL; Diet, Carbohydrate-Restricted; Diet, Fat-Restricted; Diet, Mediterranean; Humans; Network Meta-Analysis; Nutrients; Obesity; Randomized Controlled Trials as Topic; Risk Reduction Behavior; Weight Loss
PubMed: 32238384
DOI: 10.1136/bmj.m696 -
BMJ (Clinical Research Ed.) Aug 2019To investigate whether vitamin D supplementation is associated with lower mortality in adults. (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To investigate whether vitamin D supplementation is associated with lower mortality in adults.
DESIGN
Systematic review and meta-analysis of randomised controlled trials.
DATA SOURCES
Medline, Embase, and the Cochrane Central Register from their inception to 26 December 2018.
ELIGIBILITY CRITERIA FOR SELECTING STUDIES
Randomised controlled trials comparing vitamin D supplementation with a placebo or no treatment for mortality were included. Independent data extraction was conducted and study quality assessed. A meta-analysis was carried out by using fixed effects and random effects models to calculate risk ratio of death in the group receiving vitamin D supplementation and the control group.
MAIN OUTCOME MEASURES
All cause mortality.
RESULTS
52 trials with a total of 75 454 participants were identified. Vitamin D supplementation was not associated with all cause mortality (risk ratio 0.98, 95% confidence interval 0.95 to 1.02, I=0%), cardiovascular mortality (0.98, 0.88 to 1.08, 0%), or non-cancer, non-cardiovascular mortality (1.05, 0.93 to 1.18, 0%). Vitamin D supplementation statistically significantly reduced the risk of cancer death (0.84, 0.74 to 0.95, 0%). In subgroup analyses, all cause mortality was significantly lower in trials with vitamin D supplementation than in trials with vitamin D supplementation (P for interaction=0.04); neither vitamin D nor vitamin D was associated with a statistically significant reduction in all cause mortality.
CONCLUSIONS
Vitamin D supplementation alone was not associated with all cause mortality in adults compared with placebo or no treatment. Vitamin D supplementation reduced the risk of cancer death by 16%. Additional large clinical studies are needed to determine whether vitamin D supplementation is associated with lower all cause mortality.
STUDY REGISTRATION
PROSPERO registration number CRD42018117823.
Topics: Cholecalciferol; Dietary Supplements; Ergocalciferols; Humans; Mortality; Neoplasms; Randomized Controlled Trials as Topic; Vitamin D
PubMed: 31405892
DOI: 10.1136/bmj.l4673 -
Annals of Internal Medicine Mar 2023The role of vitamin D in people who are at risk for type 2 diabetes remains unclear. (Meta-Analysis)
Meta-Analysis Review
Vitamin D and Risk for Type 2 Diabetes in People With Prediabetes : A Systematic Review and Meta-analysis of Individual Participant Data From 3 Randomized Clinical Trials.
BACKGROUND
The role of vitamin D in people who are at risk for type 2 diabetes remains unclear.
PURPOSE
To evaluate whether administration of vitamin D decreases risk for diabetes among people with prediabetes.
DATA SOURCES
PubMed, Embase, and ClinicalTrials.gov from database inception through 9 December 2022.
STUDY SELECTION
Eligible trials that were specifically designed and conducted to test the effects of oral vitamin D versus placebo on new-onset diabetes in adults with prediabetes.
DATA EXTRACTION
The primary outcome was time to event for new-onset diabetes. Secondary outcomes were regression to normal glucose regulation and adverse events. Prespecified analyses (both unadjusted and adjusted for key baseline variables) were conducted according to the intention-to-treat principle.
DATA SYNTHESIS
Three randomized trials were included, which tested cholecalciferol, 20 000 IU (500 mcg) weekly; cholecalciferol, 4000 IU (100 mcg) daily; or eldecalcitol, 0.75 mcg daily, versus matching placebos. Trials were at low risk of bias. Vitamin D reduced risk for diabetes by 15% (hazard ratio, 0.85 [95% CI, 0.75 to 0.96]) in adjusted analyses, with a 3-year absolute risk reduction of 3.3% (CI, 0.6% to 6.0%). The effect of vitamin D did not differ in prespecified subgroups. Among participants assigned to the vitamin D group who maintained an intratrial mean serum 25-hydroxyvitamin D level of at least 125 nmol/L (≥50 ng/mL) compared with 50 to 74 nmol/L (20 to 29 ng/mL) during follow-up, cholecalciferol reduced risk for diabetes by 76% (hazard ratio, 0.24 [CI, 0.16 to 0.36]), with a 3-year absolute risk reduction of 18.1% (CI, 11.7% to 24.6%). Vitamin D increased the likelihood of regression to normal glucose regulation by 30% (rate ratio, 1.30 [CI, 1.16 to 1.46]). There was no evidence of difference in the rate ratios for adverse events (kidney stones: 1.17 [CI, 0.69 to 1.99]; hypercalcemia: 2.34 [CI, 0.83 to 6.66]; hypercalciuria: 1.65 [CI, 0.83 to 3.28]; death: 0.85 [CI, 0.31 to 2.36]).
LIMITATIONS
Studies of people with prediabetes do not apply to the general population. Trials may not have been powered for safety outcomes.
CONCLUSION
In adults with prediabetes, vitamin D was effective in decreasing risk for diabetes.
PRIMARY FUNDING SOURCE
None. (PROSPERO: CRD42020163522).
Topics: Adult; Humans; Diabetes Mellitus, Type 2; Prediabetic State; Dietary Supplements; Randomized Controlled Trials as Topic; Vitamin D; Vitamins; Cholecalciferol; Glucose
PubMed: 36745886
DOI: 10.7326/M22-3018 -
JAMA Network Open Dec 2019Vitamin D and calcium supplements are recommended for the prevention of fracture, but previous randomized clinical trials (RCTs) have reported conflicting results, with... (Review)
Review Meta-Analysis
IMPORTANCE
Vitamin D and calcium supplements are recommended for the prevention of fracture, but previous randomized clinical trials (RCTs) have reported conflicting results, with uncertainty about optimal doses and regimens for supplementation and their overall effectiveness.
OBJECTIVE
To assess the risks of fracture associated with differences in concentrations of 25-hydroxyvitamin D (25[OH]D) in observational studies and the risks of fracture associated with supplementation with vitamin D alone or in combination with calcium in RCTs.
DATA SOURCES
PubMed, EMBASE, Cochrane Library, and other RCT databases were searched from database inception until December 31, 2018. Searches were performed between July 2018 and December 2018.
STUDY SELECTION
Observational studies involving at least 200 fracture cases and RCTs enrolling at least 500 participants and reporting at least 10 incident fractures were included. Randomized clinical trials compared vitamin D or vitamin D and calcium with control.
DATA EXTRACTION AND SYNTHESIS
Two researchers independently extracted data according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and assessed possible bias. Rate ratios (RRs) were estimated using fixed-effects meta-analysis. Data extraction and synthesis took place between July 2018 and June 2019.
MAIN OUTCOMES AND MEASURES
Any fracture and hip fracture.
RESULTS
In a meta-analysis of 11 observational studies (39 141 participants, 6278 fractures, 2367 hip fractures), each increase of 10.0 ng/mL (ie, 25 nmol/L) in 25 (OH)D concentration was associated with an adjusted RR for any fracture of 0.93 (95% CI, 0.89-0.96) and an adjusted RR for hip fracture of 0.80 (95% CI, 0.75-0.86). A meta-analysis of 11 RCTs (34 243 participants, 2843 fractures, 740 hip fractures) of vitamin D supplementation alone (daily or intermittent dose of 400-30 000 IU, yielding a median difference in 25[OH]D concentration of 8.4 ng/mL) did not find a reduced risk of any fracture (RR, 1.06; 95% CI, 0.98-1.14) or hip fracture (RR, 1.14; 95% CI, 0.98-1.32), but these trials were constrained by infrequent intermittent dosing, low daily doses of vitamin D, or an inadequate number of participants. In contrast, a meta-analysis of 6 RCTs (49 282 participants, 5449 fractures, 730 hip fractures) of combined supplementation with vitamin D (daily doses of 400-800 IU, yielding a median difference in 25[OH]D concentration of 9.2 ng/mL) and calcium (daily doses of 1000-1200 mg) found a 6% reduced risk of any fracture (RR, 0.94; 95% CI, 0.89-0.99) and a 16% reduced risk of hip fracture (RR, 0.84; 95% CI, 0.72-0.97).
CONCLUSIONS AND RELEVANCE
In this systematic review and meta-analysis, neither intermittent nor daily dosing with standard doses of vitamin D alone was associated with reduced risk of fracture, but daily supplementation with both vitamin D and calcium was a more promising strategy.
Topics: Bone Density Conservation Agents; Bone and Bones; Calcitriol; Dietary Supplements; Fractures, Bone; Hip Fractures; Humans; Randomized Controlled Trials as Topic; Vitamin D
PubMed: 31860103
DOI: 10.1001/jamanetworkopen.2019.17789 -
The American Journal of Clinical... Aug 2015Dietary cholesterol has been suggested to increase the risk of cardiovascular disease (CVD), which has led to US recommendations to reduce cholesterol intake. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Dietary cholesterol has been suggested to increase the risk of cardiovascular disease (CVD), which has led to US recommendations to reduce cholesterol intake.
OBJECTIVE
The authors examine the effects of dietary cholesterol on CVD risk in healthy adults by using systematic review and meta-analysis.
DESIGN
MEDLINE, Cochrane Central, and Commonwealth Agricultural Bureau Abstracts databases were searched through December 2013 for prospective studies that quantified dietary cholesterol. Investigators independently screened citations and verified extracted data on study and participant characteristics, outcomes, and quality. Random-effect models meta-analysis was used when at least 3 studies reported the same CVD outcome.
RESULTS
Forty studies (17 cohorts in 19 publications with 361,923 subjects and 19 trials in 21 publications with 632 subjects) published between 1979 and 2013 were eligible for review. Dietary cholesterol was not statistically significantly associated with any coronary artery disease (4 cohorts; no summary RR), ischemic stroke (4 cohorts; summary RR: 1.13; 95% CI: 0.99, 1.28), or hemorrhagic stroke (3 cohorts; summary RR: 1.09; 95% CI: 0.79, 1.50). Dietary cholesterol statistically significantly increased both serum total cholesterol (17 trials; net change: 11.2 mg/dL; 95% CI: 6.4, 15.9) and low-density lipoprotein (LDL) cholesterol (14 trials; net change: 6.7 mg/dL; 95% CI: 1.7, 11.7 mg/dL). Increases in LDL cholesterol were no longer statistically significant when intervention doses exceeded 900 mg/d. Dietary cholesterol also statistically significantly increased serum high-density lipoprotein cholesterol (13 trials; net change: 3.2 mg/dL; 95% CI: 0.9, 9.7 mg/dL) and the LDL to high-density lipoprotein ratio (5 trials; net change: 0.2; 95% CI: 0.0, 0.3). Dietary cholesterol did not statistically significantly change serum triglycerides or very-low-density lipoprotein concentrations.
CONCLUSION
Reviewed studies were heterogeneous and lacked the methodologic rigor to draw any conclusions regarding the effects of dietary cholesterol on CVD risk. Carefully adjusted and well-conducted cohort studies would be useful to identify the relative effects of dietary cholesterol on CVD risk.
Topics: Brain Ischemia; Cardiovascular Diseases; Cholesterol; Cholesterol, Dietary; Cholesterol, HDL; Cholesterol, LDL; Coronary Artery Disease; Evidence-Based Medicine; Hemorrhagic Disorders; Humans; Non-Randomized Controlled Trials as Topic; Randomized Controlled Trials as Topic; Reproducibility of Results; Risk Factors; Stroke
PubMed: 26109578
DOI: 10.3945/ajcn.114.100305 -
Nutrients Dec 2020The rise in obesity has emphasised a focus on lifestyle and dietary habits. We aimed to address the debate between low-carbohydrate and low-fat diets and compare their... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The rise in obesity has emphasised a focus on lifestyle and dietary habits. We aimed to address the debate between low-carbohydrate and low-fat diets and compare their effects on body weight, low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), total cholesterol, and triglycerides in an adult population.
METHOD
Medline and Web of Science were searched for randomised controlled trials (RCTs) comparing low-fat and low-carbohydrate diets up to September 2019. Three independent reviewers extracted data. Risk of bias was assessed using the Cochrane tool. The meta-analysis was stratified by follow-up time using the random-effects models.
RESULTS
This meta-analysis of 38 studies assessed a total of 6499 adults. At 6-12 months, pooled analyses of mean differences of low-carbohydrate vs. low-fat diets favoured the low-carbohydrate diet for average weight change (mean difference -1.30 kg; 95% CI -2.02 to -0.57), HDL (0.05 mmol/L; 95% CI 0.03 to 0.08), and triglycerides (TG) (-0.10 mmol/L; -0.16 to -0.04), and favoured the low-fat diet for LDL (0.07 mmol/L; 95% CI 0.02 to 0.12) and total cholesterol (0.10 mmol/L; 95% CI 0.02 to 0.18). Conclusion and Relevance: This meta-analysis suggests that low-carbohydrate diets are effective at improving weight loss, HDL and TG lipid profiles. However, this must be balanced with potential consequences of raised LDL and total cholesterol in the long-term.
Topics: Adult; Cholesterol, HDL; Cholesterol, LDL; Diet, Carbohydrate-Restricted; Diet, Fat-Restricted; Humans; Lipids; Triglycerides; Weight Loss
PubMed: 33317019
DOI: 10.3390/nu12123774 -
Progress in Cardiovascular Diseases 2018The evidence for the Portfolio dietary pattern, a plant-based dietary pattern that combines recognized cholesterol-lowering foods (nuts, plant protein, viscous fibre,... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The evidence for the Portfolio dietary pattern, a plant-based dietary pattern that combines recognized cholesterol-lowering foods (nuts, plant protein, viscous fibre, plant sterols), has not been summarized.
OBJECTIVE
To update the European Association for the Study of Diabetes clinical practice guidelines for nutrition therapy, we conducted a systematic review and meta-analysis of controlled trials using GRADE of the effect of the Portfolio dietary pattern on the primary therapeutic lipid target for cardiovascular disease prevention, low-density lipoprotein cholesterol (LDL-C), and other established cardiometabolic risk factors.
METHODS
We searched MEDLINE, EMBASE, and The Cochrane Library through April 19, 2018. We included controlled trials ≥ 3-weeks assessing the effect of the Portfolio dietary pattern on cardiometabolic risk factors compared with an energy-matched control diet free of Portfolio dietary pattern components. Two independent reviewers extracted data and assessed risk of bias. The primary outcome was LDL-C. Data were pooled using the generic inverse-variance method and expressed as mean differences (MDs) with 95% confidence intervals (CIs). Heterogeneity was assessed (Cochran Q statistic) and quantified (I-statistic). GRADE assessed the certainty of the evidence.
RESULTS
Eligibility criteria were met by 7 trial comparisons in 439 participants with hyperlipidemia, in which the Portfolio dietary pattern was given on a background of a National Cholesterol Education Program (NCEP) Step II diet. The combination of a portfolio dietary pattern and NCEP Step II diet significantly reduced the primary outcome LDL-C by ~17% (MD, -0.73 mmol/L, [95% CI, -0.89 to -0.56 mmol/L]) as well as non-high-density lipoprotein cholesterol, apolipoprotein B, total cholesterol, triglycerides, systolic and diastolic blood pressure, C-reactive protein, and estimated 10-year coronary heart disease (CHD) risk, compared with an NCEP Step 2 diet alone (p < 0.05). There was no effect on high-density lipoprotein cholesterol or body weight. The certainty of the evidence was high for LDL-cholesterol and most lipid outcomes and moderate for all others outcomes.
CONCLUSIONS
Current evidence demonstrates that the Portfolio dietary pattern leads to clinically meaningful improvements in LDL-C as well as other established cardiometabolic risk factors and estimated 10-year CHD risk.
Topics: Blood Pressure; Body Weight; Cardiovascular Diseases; Diet, Healthy; Diet, Vegetarian; Evidence-Based Medicine; Feeding Behavior; Humans; Inflammation Mediators; Lipids; Nutritional Status; Nutritive Value; Prognosis; Protective Factors; Randomized Controlled Trials as Topic; Risk Factors; Risk Reduction Behavior
PubMed: 29807048
DOI: 10.1016/j.pcad.2018.05.004 -
Human Reproduction Update Nov 2022Lifestyle (dietary and/or physical activity [PA]) modification is recommended as first-line therapy to manage polycystic ovary syndrome (PCOS). Current recommendations... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Lifestyle (dietary and/or physical activity [PA]) modification is recommended as first-line therapy to manage polycystic ovary syndrome (PCOS). Current recommendations are based on healthy lifestyle practices for the general public since evidence for unique lifestyle approaches in PCOS is limited and low quality.
OBJECTIVE AND RATIONALE
We aimed to synthesize evidence on dietary and PA behaviors between women with PCOS and those without PCOS. Primary outcomes were overall diet quality, total energy intake and total PA, and secondary outcomes included macronutrients, micronutrients, food groups, foods, glycemic indices, sedentary time and sitting levels. We conducted this work to identify any unique lifestyle behaviors in women with PCOS that could underlie the propensity of weight gain and obesity in PCOS and be targeted for precision nutrition and PA interventions. These findings could be used to inform future practice recommendations and research that more effectively address complications (weight gain, obesity, diabetes, infertility, cardiovascular disease and mental health) in this high-risk population.
SEARCH METHODS
Databases of MEDLINE, Web of Science, Scopus and CINAHL were searched until 15 February 2022 to identify observational studies documenting dietary and PA behaviors between women with PCOS and without PCOS (Controls). Studies on children, adolescents (<18 years), pregnant or menopausal-aged women (>50 years) were excluded. Data were pooled by random-effects models and expressed as (standardized) mean differences (MD) and 95% CIs. The risk of bias was assessed by the Newcastle-Ottawa scale (NOS).
OUTCOMES
Fifty-four studies (N = 39 471 participants; [n = 8736 PCOS; 30 735 Controls]) were eligible (96%; [52/54] NOS scores ≥ 7). Women with PCOS had higher cholesterol (MD: 12.78, 95% CI: 1.48 to 24.08 mg/day; P = 0.03; I2 = 19%), lower magnesium (MD: -21.46, 95% CI: -41.03 to -1.91 mg/day; P = 0.03; I2 = 76%), and a tendency for lower zinc (MD: -1.08, 95% CI: -2.19 to -0.03 mg/day; P = 0.05; I2 = 96%) intake, despite lower alcohol consumption (MD: -0.95, 95% CI: -1.67 to 0.22 g/day; P = 0.02; I2 = 0%) versus Controls. Also, women with PCOS had lower total PA (standardized mean difference: -0.38, 95% CI: -0.72 to 0.03; P = 0.03; I2 = 98%). Conversely, energy, macronutrients (carbohydrate, fat, protein, fiber), micronutrients (folic acid, iron, calcium, sodium), glycemic index and glycemic load were similar (all: P ≥ 0.06). Most eligible studies reported lower total adherence to healthy eating patterns or poorer consumption of major food groups (grains, fruits, vegetables, proteins, seeds, nuts, dairy) in women with PCOS, as described narratively since variable study methodology did not permit meta-analyses.
WIDER IMPLICATIONS
Collective evidence supports that women with PCOS have a lower overall diet quality, poorer dietary intakes (higher cholesterol, lower magnesium and zinc) and lower total PA, despite lower alcohol consumption versus those without PCOS. Considerable heterogeneity among studies reinforces the need for research to address any relative contributions of other factors (e.g. genetic, metabolic or sociodemographic) to the observed differences. These clarifications may contribute to future evidence-based guideline recommendations on monitoring and managing PCOS in the era of precision lifestyle medicine.
Topics: Adolescent; Child; Female; Humans; Aged; Polycystic Ovary Syndrome; Magnesium; Diet; Obesity; Exercise; Weight Gain; Micronutrients; Zinc; Cholesterol
PubMed: 35639552
DOI: 10.1093/humupd/dmac023 -
JAMA Sep 2016The comparative clinical benefit of nonstatin therapies that reduce low-density lipoprotein cholesterol (LDL-C) remains uncertain. (Meta-Analysis)
Meta-Analysis Review
IMPORTANCE
The comparative clinical benefit of nonstatin therapies that reduce low-density lipoprotein cholesterol (LDL-C) remains uncertain.
OBJECTIVE
To evaluate the association between lowering LDL-C and relative cardiovascular risk reduction across different statin and nonstatin therapies.
DATA SOURCES AND STUDY SELECTION
The MEDLINE and EMBASE databases were searched (1966-July 2016). The key inclusion criteria were that the study was a randomized clinical trial and the reported clinical outcomes included myocardial infarction (MI). Studies were excluded if the duration was less than 6 months or had fewer than 50 clinical events. Studies of 9 different types of LDL-C reduction approaches were included.
DATA EXTRACTION AND SYNTHESIS
Two authors independently extracted and entered data into standardized data sheets and data were analyzed using meta-regression.
MAIN OUTCOMES AND MEASURES
The relative risk (RR) of major vascular events (a composite of cardiovascular death, acute MI or other acute coronary syndrome, coronary revascularization, or stroke) associated with the absolute reduction in LDL-C level; 5-year rate of major coronary events (coronary death or MI) associated with achieved LDL-C level.
RESULTS
A total of 312 175 participants (mean age, 62 years; 24% women; mean baseline LDL-C level of 3.16 mmol/L [122.3 mg/dL]) from 49 trials with 39 645 major vascular events were included. The RR for major vascular events per 1-mmol/L (38.7-mg/dL) reduction in LDL-C level was 0.77 (95% CI, 0.71-0.84; P < .001) for statins and 0.75 (95% CI, 0.66-0.86; P = .002) for established nonstatin interventions that work primarily via upregulation of LDL receptor expression (ie, diet, bile acid sequestrants, ileal bypass, and ezetimibe) (between-group difference, P = .72). For these 5 therapies combined, the RR was 0.77 (95% CI, 0.75-0.79, P < .001) for major vascular events per 1-mmol/L reduction in LDL-C level. For other interventions, the observed RRs vs the expected RRs based on the degree of LDL-C reduction in the trials were 0.94 (95% CI, 0.89-0.99) vs 0.91 (95% CI, 0.90-0.92) for niacin (P = .24); 0.88 (95% CI, 0.83-0.92) vs 0.94 (95% CI, 0.93-0.94) for fibrates (P = .02), which was lower than expected (ie, greater risk reduction); 1.01 (95% CI, 0.94-1.09) vs 0.90 (95% CI, 0.89-0.91) for cholesteryl ester transfer protein inhibitors (P = .002), which was higher than expected (ie, less risk reduction); and 0.49 (95% CI, 0.34-0.71) vs 0.61 (95% CI, 0.58-0.65) for proprotein convertase subtilisin/kexin type 9 inhibitors (P = .25). The achieved absolute LDL-C level was significantly associated with the absolute rate of major coronary events (11 301 events, including coronary death or MI) for primary prevention trials (1.5% lower event rate [95% CI, 0.5%-2.6%] per each 1-mmol/L lower LDL-C level; P = .008) and secondary prevention trials (4.6% lower event rate [95% CI, 2.9%-6.4%] per each 1-mmol/L lower LDL-C level; P < .001).
CONCLUSIONS AND RELEVANCE
In this meta-regression analysis, the use of statin and nonstatin therapies that act via upregulation of LDL receptor expression to reduce LDL-C were associated with similar RRs of major vascular events per change in LDL-C. Lower achieved LDL-C levels were associated with lower rates of major coronary events.
Topics: Cardiovascular Diseases; Cholesterol, LDL; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypolipidemic Agents; Male; Middle Aged; Myocardial Infarction; Niacin; Receptors, LDL; Risk Reduction Behavior; Stroke; Up-Regulation
PubMed: 27673306
DOI: 10.1001/jama.2016.13985