The effects of alpha-lipoic acid supplementation on glucose control and lipid profiles among patients with metabolic diseases: A systematic review and meta-analysis of randomized controlled trials

Abstract Objective This systematic review and meta-analysis of randomized controlled trials (RCTs) was performed to summarize the effect of alpha-lipoic acid (ALA) supplementation on glycemic control and lipid profiles among patients with metabolic diseases. Methods We searched the following databases till October 2017: MEDLINE, EMBASE, Web of Science and Cochrane Central Register of Controlled Trials. The relevant data were extracted and assessed for quality of the studies according to the Cochrane risk of bias tool. Data were pooled using the inverse variance method and expressed as standardized mean difference (SMD) with 95% confidence intervals (95% CI). Heterogeneity between studies was assessed by the Cochran Q statistic and I-squared tests (I2). Twenty-four studies were included in the meta-analyses. Results The findings of this meta-analysis showed that ALA supplementation among patients with metabolic diseases significantly decreased fasting glucose (SMD -0.54; 95% CI, −0.89, –0.19; P = 0.003), insulin (SMD –1.01; 95% CI, −1.70, −0.31; P = 0.006), homeostasis model assessment of insulin resistance (SMD -0.76; 95% CI, −1.15, –0.36; P < 0.001) and hemoglobin A1c (SMD –1.22; 95% CI, −2.01, –0.44; P = 0.002), triglycerides (SMD –0.58; 95% CI, −1.00, −0.16; P = 0.006), total- (SMD –0.64; 95% CI, −1.01, −0.27; P = 0.001), low density lipoprotein-cholesterol (SMD –0.44; 95% CI, −0.76, −0.11; P = 0.008). We found no detrimental effect of ALA supplementation on high density lipoprotein-cholesterol (HDL-cholesterol) levels (SMD 0.57; 95% CI, −0.14, 1.29; P = 0.11). Conclusions Overall, the current meta-analysis demonstrated that ALA administration may lead to an improvement in glucose homeostasis parameters and lipid profiles except HDL-cholesterol levels. Keywords: Meta-analysis Lipid profiles Glycemic control Alpha-lipoic acid

Estimating the completeness of lung cancer registry in Ardabil, Iran with a three-source capture-recapture method

Cancer registration is an important component of a comprehensive cancer control program, providing timely data and information for research and administrative use. Capture-recapture methods have been used as tools to investigate completeness of cancer registry data. This study aimed to estimate the completeness of lung cancer cases registered in Ardabil Population Based Cancer Registry (APBCR) with a three-source capture-recapture method. Data for all new cases of lung cancer reported by three sources (pathology reports, death certificates, and medical records) to APBCR for 2006 and 2008 were obtained. Duplicate cases shared among the three sources were identified based on similarity of first name, last name and father's names. A log-linear model was used to estimate number of missed cases and to control for dependency among sources. A total of 218 new cases of lung cancer was reported by three sources after removing duplicates. The estimated completeness calculated by log-linear method was 26.4 for 2006 and 27.1 for 2008. The completeness differed according to gender. In men, the completeness was 26.0 for 2006 and 28.1 for 2008. In women, the completeness was 36.5 for 2006 and 46.9 for 2008. In conclusion, none of the three sources can be considered as a reliable source for accurate cancer incidence estimation. © 2016, Asian Pacific Journal of Cancer Prevention

Estimating the esophagus cancer incidence rate in Ardabil, Iran: A capture-recapture method

Background: Accurate cancer registry and awareness of cancer incidence rate is essential in order to define strategies for cancer prevention and control programs. Capture-recapture methods have been recommended for reducing bias and increase the accuracy of cancer incidence estimation. Objectives: This study aimed to estimate the esophagus cancer incidence by capture-recapture method based on Ardabil population-based cancer registry data. Patients and Methods: Total new cases of esophagus cancer reported by three sources of pathology reports, medical records, and death certificates to Ardabil province cancer registry center in 2006 and 2008 were enrolled in the study. All duplicated cases between three sources were identified and removed using Excel software. Some characteristics such as name, surname, father�s name, date of birth and ICD codes related to their cancer type were used for data linkage and finding the common cases among three sources. The incidence rate per 100,000 was estimated based on capture-recapture method using the log-linear models. We used BIC, G2 and AIC statistics to select the best-fit model. Results: After removing duplicates, total 471 new cases of esophagus cancer were reported from three sources. The model with linkage between pathology reports, medical record sources and independence with the death certificates source was the best fitted model. The reported incidence rate for the years 2006 and 2008 was 18.77 and 18.51 per 100,000, respectively. In log-linear analysis, the estimated incidence rate for the years 2006 and 2008 was 49.71 and 53.87 per 100,000 populations, respectively. Conclusions: Based on the obtained results, it can be concluded that none of the sources of pathology reports, death certificates and medical records individually or collectively were fully covered the incidence cases of esophagus cancer and need to apply some changes in data abstracting and case finding. © 2016, Iranian Journal of Cancer Prevention

Estimating the completeness of lung cancer registry in Ardabil, Iran with a three-source capture-recapture method

Cancer registration is an important component of a comprehensive cancer control program, providing timely data and information for research and administrative use. Capture-recapture methods have been used as tools to investigate completeness of cancer registry data. This study aimed to estimate the completeness of lung cancer cases registered in Ardabil Population Based Cancer Registry (APBCR) with a three-source capture-recapture method. Data for all new cases of lung cancer reported by three sources (pathology reports, death certificates, and medical records) to APBCR for 2006 and 2008 were obtained. Duplicate cases shared among the three sources were identified based on similarity of first name, last name and father's names. A log-linear model was used to estimate number of missed cases and to control for dependency among sources. A total of 218 new cases of lung cancer was reported by three sources after removing duplicates. The estimated completeness calculated by log-linear method was 26.4 for 2006 and 27.1 for 2008. The completeness differed according to gender. In men, the completeness was 26.0 for 2006 and 28.1 for 2008. In women, the completeness was 36.5 for 2006 and 46.9 for 2008. In conclusion, none of the three sources can be considered as a reliable source for accurate cancer incidence estimation. © 2016, Asian Pacific Journal of Cancer Prevention

Dietary total antioxidant capacity and mortality from all causes, cardiovascular disease and cancer: a systematic review and dose�response meta-analysis of prospective cohort studies

Purpose: No conclusive information is available about the association between dietary total antioxidant capacity (DTAC) and risk of mortality. Current meta-analysis of prospective cohort studies was done to summarize available findings on the association between DTAC and risk of death from all-cause, cancer and cardiovascular diseases (CVDs). Methods: Online databases were searched to detect relevant publications up to January 2018, using relevant keywords. To pool data, either fixed-effects or random-effects model was used. Furthermore, linear and non-linear dose�response analyses were also done. Results: In total, five prospective studies were included in the current systematic review and meta-analysis. In a follow-up period of 4.3�16.5 years, there were 38,449 deaths from all-cause, 4470 from cancer and 2841 from CVDs among 226,297 individuals. A significant inverse association was found between DTAC and all-cause mortality (combined effect size: 0.62, 95 CI 0.60�0.64). Such finding was also seen for cancer (combined effect size: 0.81, 95 CI 0.75�0.88) and CVD (combined effect size: 0.71, 95 CI 0.63�0.82) mortality. Findings from linear dose�response meta-analysis revealed that a 5 mmol/day increment in DTAC based on ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) was associated with 7 and 15 lower risk of all-cause mortality, respectively. Based on findings from non-linear dose�response meta-analysis, a significant reduction in risk of all-cause mortality was seen when increasing FRAP from 2 to 12 mmol/day (P-nonlinearity = 0.002) and ORAC from 5 to 11 mmol/day (P-nonlinearity < 0.001). Conclusions: Adherence to diet with high total antioxidant capacity was associated with decreased risk of death from all-cause, cancer and CVDs. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature

Dietary total antioxidant capacity and risk of cancer: a systematic review and meta-analysis on observational studies

Background: Recent studies have shown that dietary total antioxidant capacity (D-TAC) may affect risk of cancer; however, findings are conflicting. Hence, we aimed to summarize the current evidence on the association between D-TAC and risk of cancer. Methods: We searched the online databases of PubMed, ISI Web of Science, Scopus, ProQuest, Science Direct and Embase until October 2018 using relevant keywords. To pool data, fixed- or random-effects models were used where appropriate. Results: In total, 19 studies including 8 prospective and 11 case-control studies with 721429 individuals and 16159 cases of cancer were included in the current systematic review and meta-analysis. Combining 15 effect sizes from 6 prospective and 8 case-control studies revealed a significant inverse association between D-TAC (obtained from ferric reducing antioxidant power (FRAP)) and risk of cancer (combined effect size: 0.86, 95 CI: 0.81-0.92, P < 0.001). Such inverse association was also seen for D-TAC obtained from other methods including trolox equivalence antioxidant capacity (TEAC) (combined effect size: 0.80, 95 CI: 0.70�0.90, P < 0.001), total radical trapping antioxidant parameter (TRAP) (combined effect size: 0.69, 95 CI: 0.62�0.78, P < 0.001) and oxygen radical absorbance capacity (ORAC) (combined effect size: 0.72, 95 CI: 0.52�1.00, P = 0.04). In addition, a significant non-linear association was found between D-TAC (based on FRAP and TRAP) and cancer risk (P-nonlinearity<0.001). Based on linear dose-response meta-analysis, a-10 mmol/day increase in FRAP and a-5 mmol/day increase in TRAP and TEAC were associated with 9, 17 and 14 reduction in risk of cancer, respectively. Furthermore, D-TAC was inversely associated with risk of colorectal (combined effect size: 0.82, 95 CI: 0.75-0.89, P < 0.001), gastric (combined effect size: 0.63, 95 CI: 0.53-0.73, P < 0.001), and endometrial cancer (combined effect size: 0.78, 95 CI: 0.69-0.89, P < 0.001). Conclusions: Diet with high antioxidant capacity might have protective effects against cancer. © 2019 Elsevier B.V

Gestational diabetes mellitus in association with macrosomia in Iran: a meta-analysis

Purpose: This meta-analysis aimed to estimate the association between gestational diabetes mellitus (GDM) and occurrence of macrosomia for the first time among Iranian population. Methods: A systematic review was done of national and international databases. Lists of relevant articles were checked to increase sensitivity of the search reference. Also, access to unpublished articles and documents were accessed by negotiation with related individuals and research centers. These published epidemiological studies (cross-sectional, case-control and cohort studies) were used for comparisons to determine whether GDM was associated with macrosomia. Finally, the Mantel-Haenszel method and the fixed and random-effect models based on heterogeneity of the primary studies were used according to pool results and estimate the odds ratio of macrosomia in women with GDM. Results: Of 1870 articles, thirty relevant articles were eligible for the current meta-analysis. Our findings showed that 335 of 2524 women with GDM had macrosomia while only 775 of 26,592 women without GDM had macrosomia. Using random-effect model, the pooled odds ratio (OR) relation between GDM and occurrence of macrosomia was estimated as of 5.49 (95 CI: 4.27�7.04). Subgroup analysis showed no difference regarding different study designs and definitions of macrosomia. There was no evidence of publication bias based on the result of Egger�s test (β = 0.1, P = 0.70). Conclusions: This meta-analysis shows that GDM is directly associated with the risk of macrosomia in the Iranian population. This confirms the findings of previous studies in the wider scientific literature. © 2019, Springer Nature Switzerland AG

Family history of diabetes and the risk of gestational diabetes mellitus in Iran: A systematic review and meta-analysis.

OBJECTIVE Gestational diabetes is the most prevalent metabolic disorder being firstly diagnosed during pregnancy. The relationship between the family history of diabetes and the gestational diabetes mellitus (GDM) has been investigated in several primary studies with a number of contradictions in the results. Hence, the purpose of the present study is to determine the relationship between the GDM and the family history of diabetes using the meta-analysis method. METHOD All published papers in main national and international databases were systematically searched with some specific keywords to find the related studies between 2000 and 2016. We calculated the odds ratio (OR) with 95% confidence interval (CI) in analysis for each study using a random-effect and Mantel-Haenzel method. We also determined heterogeneity among these 33 articles and their publication bias. RESULTS We entered 33 relevant studies of 2516 articles into the meta-analysis process including 2697 women with family history of diabetes mellitus as well as 29134 women without. Of them, 954 and 4372 subjects developed GDM respectively. Combining the results of the primary studies using the meta-analysis method, the overall odds ratio of family history for developing GDM was estimated as of 3.46 (95% CI: 2.80-4.27). CONCLUSION This meta-analysis study revealed that the family history of diabetes is an important risk factor for the gestational diabetes mellitus