Body mass index and risk of Parkinson, Alzheimer, Dementia, and Dementia mortality: a systematic review and dose-response meta-analysis of cohort studies among 5 million participants.

Objective: Inconsistent results regarding the association between the Body Mass Index (BMI) and brain disorders have been reported. We performed this study to investigate the association between BMI and risk of Parkinson, Alzheimer, Dementia and Dementia-mortality.Methods: A systematic search was conducted up to April 2019 in MEDLINE/PubMed, SCOPUS, and Cochrane Library. Results pooled with random-effects model.Results: Totally, 29 articles which were included in this study with4,978,621 participants. The pooled HR for Parkinson's in the underweight person was 1.20 (95%CI1.10-1.30). The pooled HR for dementia in underweight and overweight category was 1.23 (95%CI = 1.05-1.45) and 0.88 (95%CI = 0.83-0.94), respectively. There is not any significant relation between each categories of BMI and Alzheimer disease. The pooled HR for dementia in underweight and overweight category was 1.36 (95%CI = 1.14-1.63) and 0.81 (95%CI = 0.49-1.33), respectively. The non-linear association between BMI and risk of Dementia-mortality was significant (p = 0.001,Coeff = 0.003).Conclusion: This study highlights underweight related to increase incidence of Parkinson, Dementia, and Dementia mortality but no on Alzheimer disease.

Relationship between body mass index, risk of venous thromboembolism and pulmonary embolism: A systematic review and dose-response meta-analysis of cohort studies among four million participants.

BACKGROUND: The relationship between body mass index (BMI) and risk of venous thromboembolism (VTE) and pulmonary embolism (PE) is a controversial issue. This dose-response meta-analysis was performed to investigate the association between BMI and risk of VTE and PE incidence based on cohort studies. METHOD: A comprehensive systematic search was conducted up to August 2019 in MEDLINE/PubMed, SCOPUS, and Cochrane. DerSimonian and Laird random-effects models were run to estimate combined hazard ratios (HRs) with 95% confidence intervals (CIs). Dose-response analysis was also carried out based on BMI values. RESULTS: Eleven articles with 16 arms and 3,910,747 participants were eligible for inclusion in this systematic review and meta-analysis. Pooled results showed a positive association between BMI and risk of VTE in the obese participants compared to participants classified in the normal BMI category (HR: 1.62, 95% CI: 1.29-2.04, I2 = 95%). Furthermore, results showed a significant association between lower BMI (underweight versus normal BMI category) and reduced risk of PE (HR: 0.80, 95% CI: 0.70-0.92, I2 = 9%) and higher risk of PE in obese versus normal BMI participants (HR: 2.24, 95% CI: 1.93-2.60, I2 = 0%). There was a significant linear relationship between BMI and risk of VTE (p < 0.001) and PE (p < 0.001). CONCLUSIONS: This systematic review and dose-response meta-analysis with 3,910,747 participants highlights obesity as a significant risk factor related to the incidence of VTE and PE.

Effect of tomato consumption on fasting blood glucose and lipid profiles: A systematic review and meta-analysis of randomized controlled trials.

Tomato (Solanum lycopersicum) phytochemicals, which include phytoene, phytofluene, beta-carotene, flavonoids, lycopene, and polyphenols, have been shown to improve the effects of fasting on plasma triglyceride (TG), low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), total cholesterol (TC), and fasting blood sugar (FBS). The aim of this study was to systematically evaluate the effects of Tomato TC, TG, HDL, LDL, and FBS in humans. A systematic literature search was conducted in PubMed/MEDLINE, Web of sciences, and SCOPUS databases by two researchers for studies published until August of 2019 without language and time limitations. Results were combined with random effect models. Six studies were included in this meta-analysis. Combined results reveal a significant reduction in cholesterol (weighted mean difference [WMD]: -4.39 mg/dl, 95% CI: -7.09, -1.68, I2 = % 48, p heterogeneity: .05), TG (WMD: -3.94 mg/dl, 95% CI: -7.67, -0.21, I2 = % 90, p heterogeneity: .001), LDL levels (WMD: -2.09 mg/dl, 95% CI: -3.73, -0.81, I2 = % 78, p heterogeneity: .001), and increasing in HDL levels (WMD: 2.25 mg/dl, 95% CI: 0.41, 4.10, I2 = % 97, p heterogeneity: .001). Tomato was found to have a higher reduction effect on TG and LDL in younger participants. While pooled results indicate no significant effect on FBS levels (WMD: 0.59 mg/dl, 95% CI: -0.28, 1.46, I2 = % 95, p heterogeneity: .001). In conclusion, the results indicate a significant reduction in total cholesterol, TG, and LDL and increase in HDL levels that is caused by tomato consumption.

Association of aspirin therapy with risk of hepatocellular carcinoma: A systematic review and dose-response analysis of cohort studies with 2.5 million participants.

Although aspirin is commonly used for the prevention of cardiovascular disease, evidence from research has shown that these beneficial effects might extend to hepatocellular carcinoma (HCC). This dose-response analysis was performed to investigate the association between aspirin use and risk of HCC. A systematic search was conducted in MEDLINE/PubMed, SCOPUS, Cochrane, and Web of Science databases from inception up to 29th October 2019. DerSimonian and Laird Random-effects model was used to estimate pooled hazard ratios (HRs) from included studies. Overall, eight studies containing 2,604,319 participants evaluating the association between aspirin use and risk of HCC were uncovered and included in the present meta-analysis. Pooled results of included studies showed a significant reduction in risk of HCC in participants who used aspirin (HR 0.59, 95 % CI 0.47-0.75, Pheterogeneity = 0.001, I2 = 90 %). In total, 13,636 cases of HCC detected during the follow-up period of these studies. Furthermore, linear dose-response model showed an significant inverse association between aspirin dose and risk of HCC (exp (b) = 0.994, p < 0.001), while non-linear dose-response analysis revealed an even more robust association (Coef1=-0.008, p1 = 0.04, Coef2 = 0.033, p2 = 0.13). This systematic review and dose-response analysis identified significant inverse relation between aspirin and risk of HCC using both linear and non-linear models.

The association of plasma levels of liver enzymes and risk of gestational diabetes mellitus: a systematic review and dose-response meta-analysis of observational studies.

AIMS: Relationship between liver enzymes such as gamma-glutamyl transferase (GGT), alanine aminotransferase (ALT), aspartate transaminase (AST) and alkaline phosphatase and risk of gestational diabetes mellitus (GDM) is a controversial issue. The aim of this systematic review and dose-response meta-analysis was to investigate the association between liver enzymes and risk of GDM in observational studies. METHODS: A comprehensive systematic literature search was conducted in MEDLINE/PubMed, SCOPUS and Web of Science databases up to September 2019. Combined odds ratios (ORs) with 95% confidence intervals (CIs) were evaluated by DerSimonian and Laird random-effects models. Dose-response analyses of these relationships were also carried out. RESULTS: Eight studies with 25,451 participants containing 2549 cases were included in this study. Pooled results showed a significant association between GGT levels and risk of GDM (OR 2.10, 95% CI 1.14-3.86, I2 84%). In addition, random-effects model indicated a dramatic and direct significant association between GGT and risk of GDM in nonlinear (p < 0.001) and linear (p < 0.001) dose-response analysis. Associations between ALT and AST with risk of GDM were found to be non-significant (OR 1.32, 95% CI 0.91-1.90, I2 65% and OR 0.76, 95% CI 0.52-1.10, I2 16%, respectively). CONCLUSION: This systematic review and dose-response meta-analysis highlights GGT as a significant and robust predictor of the incidence of GDM in pregnant women.

The relationship between dietary antioxidant intake and physical activity rate with nonalcoholic fatty liver disease (NAFLD): A case - Control study.

INTRODUCTION: Although dietary intakes, especially micronutrients, can be associated with the severity of nonalcoholic fatty liver disease (NAFLD), investigations on the amount of vitamins and antioxidants consumption and their relationship with NAFLD are very limited and incomplete. Therefore, we decided to investigate the relationship between antioxidant compounds intake and physical activity rate with NAFLD. METHODS: In this study, 200 patients with NAFLD for the case group and 400 healthy subjects for the control group were selected. Patients were diagnosed as NAFLD after giving blood tests and performing Ultrasonography by a radiology specialist. Dietary intakes were evaluated through a validated 168-items semi-quantitative food frequency questionnaire (FFQ). Physical activity rate was estimated by a validated short form of International Physical Activity Questionnaire (Short IPAQ). RESULTS: The study population was between 20 and 60 years old and 46% of them were women. Weight, waist circumference, hip circumference, WHR, and BMI in the cases were higher than the controls. Physical activity comparisons showed that controls had higher physical activity rate than cases. Mean consumption of vitamins C, A, D and alpha-tocopherol in case group was less than the other group. After adjustment for all potential confounder, subjects who were in highest tertile of vitamin A intake -in comparison to those in the lowest tertile of intake-decreased risk of NAFLD (OR = 0.40, 95%CI: 0.30-0.55). The same finding was obtained for vitamin D; [Top category vs. bottom category of vitamin D of intake (OR = 0.35, 95%CI: 0.20-0.61)]. CONCLUSIONS: We found that more intakes of vitamins A and D are related to lower risk of NAFLD in this group of Iranian adults. Physical activity rate in cases was less than the controls. Further prospective studies are required to confirm causal association between antioxidant compounds intake and NAFLD.

Body mass index and risk of inflammatory bowel disease: A systematic review and dose-response meta-analysis of cohort studies of over a million participants.

The relationship between body mass index (BMI) and risk of inflammatory bowel disease (IBD) is controversial. We performed a dose-response meta-analysis to investigate the association between BMI and risk of incident ulcerative colitis (UC) and Crohn's disease (CD) using prospective cohort studies. A systematic search was conducted in MEDLINE/PubMed, SCOPUS, Cochrane, and Web of Science databases from inception to January 2019. DerSimonian and Laird random-effects model was used to estimate combined hazard ratios (HRs). Overall, 882 articles were screened, and 42 full-text articles were reviewed for inclusion using the study eligibility criteria. Five studies evaluated the association between BMI and IBD with 1 044 517 participants. Pooled results showed a significant association between participants affected by obesity and risk of CD (HR: 1.42, 95% CI: 1.18-1.71, I2 : 0.00). There was a significant nonlinear association between BMI and risk of CD (P = .01, coeff = 0.5024). Pooled results did not show any significant association between being underweight and risk of UC (HR: 1.07, 95% CI: 0.96-1.19, I2 : 0.00) or CD (HR: 1.11, 95% CI: 0.93-1.31, I2 : 12.8). There was no difference in the risk for UC among participants affected by obesity compared with participants categorized as having normal BMI (HR: 0.96, 95% CI: 0.80-1.14, I2 : 8.0). This systematic review and meta-analysis identified significant dose-response relationship between being affected by obesity, as a risk factor, and incidence of CD.

Elevated liver enzymes and cardiovascular mortality: a systematic review and dose-response meta-analysis of more than one million participants.

Gamma glutamyl transferase (GGT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) are commonly used liver function markers. We performed a dose-response meta-analysis to investigate the association between liver enzymes and cardiovascular disease (CVD) mortality in prospective cohort studies. We conducted a systematic search up to April 2018 in Medline/PubMed, Scopus, Cochrane, and Embase databases. Combined hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using a random-effects model as described by DerSimonian and Laird. Dose-response analysis was also carried out. Twenty-three studies with 1 067 922 participants reported association between GGT and CVD mortality and were included in our analysis. Pooled results showed a significant association between GGT and risk of CVD mortality (HR: 1.62; 95% CI: 1.47-1.78, P=0.001, P-heterogeneity=0.001) and it was HR: 0.87; 95% CI: 0.73-1.07; P=0.221, P-heterogeneity=0.028, for ALT. There was a direct association between baseline levels of ALP and AST/ALT ratio with CVD mortality (HR: 1.45; 95% CI: 1.11-1.89; P=0.005, P-heterogeneity=0.026, and HR: 2.20; 95% CI: 1.60-3.04; P=0.001, P-heterogeneity=0.540, respectively). Pooled results did not show any significant association between AST and the risk of CVD mortality (HR: 1.20; 95% CI: 0.83-1.73; P=0.313, P-heterogeneity=0.024). Moreover, there was a significant nonlinear association between GGT and ALP levels and the risk of CVD mortality (P=0.008 and 0.016, respectively). Our dose-response meta-analysis revealed a direct relationship between GGT and ALP levels and the risk of CVD mortality. High levels of GGT, ALP and AST/ALT were associated with an increased CVD mortality rate.