Maternal Socioeconomic Status and the Risk of Congenital Heart Defects in Offspring: A Meta-Analysis of 33 Studies

Background

We conducted this meta-analysis to address the open question of a possible association between maternal socioeconomic status and congenital heart defects (CHDs).

Methods

We searched MEDLINE and EMBASE from their inception to January 1, 2014 for case-control and cohort studies that assessed the association between maternal socioeconomic status and the risk of CHDs. Study-specific relative risk estimates were polled according to random-effect or fixed-effect models.

Results

From 3343 references, a total of 31 case-control studies and 2 cohort studies were enrolled in this meta-analysis, including more than 50,000 cases. We observed that maternal educational attainment, family income and maternal occupation were negatively associated with an 11% (pooled RR = 1.11, 95% CI: 1.03, 1.21), 5% (pooled RR = 1.05, 95% CI: 1.01, 1.09) and 51% (pooled RR = 1.51, 95% CI: 1.02, 2.24) increased risk of CHDs, respectively. In a subgroup analysis by geographic region, the results were inconsistent for the European region (RR = 1.29, 95% CI: 0.99–1.69) and USA/Canada region (RR = 1.06, 95% CI: 0.97, 1.16) in maternal educational attainment.

Conclusion

In summary, this meta-analysis suggests that a lower degree of maternal socioeconomic status is modestly associated with an increased risk of CHDs. However, further investigations are needed to confirm the association.     

Maternal Parity and the Risk of Congenital Heart Defects in Offspring: A Dose-Response Meta-Analysis of Epidemiological Observational Studies

Background

Epidemiological studies have reported conflicting results regarding maternal parity and the risk of congenital heart defects (CHDs). However, a meta-analysis of the association between maternal parity and CHDs in offspring has not been conducted.

Methods

We searched MEDLINE and EMBASE for articles catalogued between their inception and March 8, 2014; we identified relevant published studies that assessed the association between maternal parity and CHD risk. Two authors independently assessed the eligibility of the retrieved articles and extracted data from them. Study-specific relative risk estimates were pooled by random-effects or fixed-effects models. From the 11272 references, a total of 16 case-control studies and 3 cohort studies were enrolled in this meta-analysis.

Results

The overall relative risk of CHD in parous versus nulliparous women was 1.01 (95% CI, 0.97–1.06; Q = 32.34; P = 0.006; I² = 53.6%). Furthermore, we observed a significant association between the highest versus lowest parity number, with an overall RR = 1.20 (95% CI, 1.10–1.31; (Q = 74.61, P<0.001, I² = 82.6%). A dose–response analysis also indicated a positive effect of maternal parity on CHD risk, and the overall increase in relative risk per one live birth was 1.06 (95% CI, 1.02–1.09); Q = 68.09; P<0.001; I² = 80.9%). We conducted stratified and meta-regression analyses to identify the origin of the heterogeneity among studies. A Galbraith plot was created to graphically assess the sources of heterogeneity.

Conclusion

In summary, this meta-analysis provided a robust estimate of the positive association between maternal parity and risk of CHD.     

PROLACTIN-Deficiency in Adult Offspring of Diabetic Mothers

Maternal diabetes induces fetal alterations, resulting in lasting consequences for the glucose tolerance of the offspring over several generations. In our experimental rat model, circulating prolactin, oestradiol, progesterone and corticosterone levels, known to influence insulin secretion and action, are determined in plasma of female adult offspring of mildly and severely diabetic mothers. Prolactin and progesterone levels are equally low in both groups as compared to controls, stressing the involvement of the CNS in the transgeneration effect; oestradiol and corticosterone levels are normal. No correlation is found between these hormonal alterations and the known differences in glucose tolerance.     

Fish and Fish Oil Intake in Relation to Risk of Asthma: A Systematic Review and Meta-Analysis

Although laboratory studies suggest that long-chain n-3 polyunsaturated fatty acids (LCn3PUFAs) may reduce risk of asthma, epidemiological data remain controversial and inconclusive. We quantitatively reviewed the epidemiological studies published through December 2012 in PubMed and EMBASE by using a fixed-effects or random-effects model. Eleven studies, comprised of 99,093 individuals (3,226 cases), were included in the final dataset. Of them, 7 studies examined associations between intake of fish or LCn3PUFA and risk of asthma: 4 studies in children (996 cases from 12,481 children) and 3 in adults (1,311 cases from 82,553 individuals). Two studies (69 cases from 276 infants) investigated LCn3PUFA levels in mothers’ milk, and two studies assessed maternal fish consumption (786 cases from 2,832 individuals) during lactation and/or plasma LCn3PUFA levels during pregnancy (64 cases from 951 infants) in relation to offspring’s asthma. The pooled relative risk of child asthma were 0.76 (95% CI, 0.61–0.94) for fish consumption and 0.71 (95% CI, 0.52–0.96) for LCn3PUFA intake. No statistically significant association was found in studies among adults. Epidemiological data to date indicate that fish or LCn3PUFA intake may be beneficial to prevent asthma in children. Further studies are needed to establish causal inference and to elucidate the potential mechanisms.     

Residential Dampness and Molds and the Risk of Developing Asthma: A Systematic Review and Meta-Analysis

Context

Studies from different geographical regions have assessed the relations between indoor dampness and mold problems and the risk of asthma, but the evidence has been inconclusive.

Objective

To assess the relations between indicators of indoor dampness and mold problems and the risk of developing new asthma, and to investigate whether such relations differ according to the type of exposure.

Data sources

A systematic literature search of PubMed database from 1990 through March 2012 and the reference lists of recent reviews and of relevant articles identified in our search.

Study selection

Cohort/longitudinal and incident case-control studies assessing the relation between mold/dampness and new asthma were included.

Data extraction

Three authors independently evaluated eligible articles and extracted relevant information using a structured form.

Synthesis

Sixteen studies were included: 11 cohort and 5 incident case-control studies. The summary effect estimates (EE) based on the highest and lowest estimates for the relation between any exposure and onset of asthma were 1.50 (95% confidence interval [CI] 1.25–1.80, random-effects model, Q-statistic 38.74 (16), P = 0.001) and 1.31 (95% CI 1.09–1.58, random-effects model, Q-statistic 40.08 (16), P = 0.000), respectively. The summary effect estimates were significantly elevated for dampness (fixed-effects model: EE 1.33, 95% CI 1.12–1.56, Q-statistic 8.22 (9), P = 0.413), visible mold (random-effects model; EE 1.29, 95% CI 1.04–1.60, 30.30 (12), P = 0.001), and mold odor (random-effects model; EE 1.73, 95% CI 1.19–2.50, Q-statistics 14.85 (8), P = 0.038), but not for water damage (fixed-effects model; EE 1.12, 95% CI 0.98–1.27). Heterogeneity was observed in the study-specific effect estimates.

Conclusion

The evidence indicates that dampness and molds in the home are determinants of developing asthma. The association of the presence of visible mold and especially mold odor to the risk of asthma points towards mold-related causal agents.     

Maternal Testosterone and Offspring Sex-Ratio in Birds and Mammals: A Meta-Analysis

Sex allocation theory predicts that parents should bias offspring sex to maximize their fitness in a given context. Quantifying the fitness benefits of offspring sex-ratio biases would be facilitated by a better knowledge of their underlying mechanism(s) and associated costs. The hypothesis that steroid hormones are involved in sex determination has gained in popularity recently. Being influenced by external stimuli and involved in a range of physiological processes, they could be a ubiquitous mediator of environmental conditions influencing sex-ratio with low fitness costs. Previous studies indicated that higher maternal testosterone levels led to the overproduction of sons around conception in both birds and mammals. We conducted a systematic review (including meta-analysis) of these studies and, as predicted, we found a weak positive and significant overall effect of maternal testosterone on the proportion of sons. Neither taxa, nor the type of study (experimental/observational), or the timing of timing testosterone manipulation/measure were significant predictors of offspring sex-ratio, which may be explained by low statistical power in addition to low variability between effect sizes. Our meta-analysis provides evidence for a general positive influence of maternal testosterone around conception on the proportion of sons across birds and mammals, although less confidently so for the latter. It begs for more large-scale experimental studies, especially on mammals, and ideally in the wild. It may also have some important consequences for the poultry industry.     

Vitamin D Supplementation for Childhood Asthma: A Systematic Review and Meta-Analysis

Importance

There is growing evidence that vitamin D plays a role in the pathogenesis of asthma but it is unclear whether supplementation during childhood may improve asthma outcomes.

Objectives

The objective of this systematic review and meta-analysis was to evaluate the efficacy and safety of vitamin D supplementation as a treatment or adjunct treatment for asthma.

Data Sources

We searched MEDLINE, Embase, CENTRAL, and CINAHL through July 2014.

Study Selection

We included RCTs that evaluated vitamin D supplementation in children versus active control or placebo for asthma.

Data Extraction and Synthesis

One reviewer extracted data and one reviewer verified data accuracy. We qualitatively summarized the main results of efficacy and safety and meta-analyzed data on comparable outcomes across studies. We used GRADE for strength of evidence.

Main Outcome Measures

Main planned outcomes measures were ED visits and hospitalizations. As secondary outcomes, we examined measures of asthma control, including frequency of asthma exacerbations, asthma symptom scores, measures of lung function, β₂-agonist use and daily steroid use, adverse events and 25-hydroxyvitamin D levels.

Results

Eight RCTs (one parallel, one crossover design) comprising 573 children aged 3 to 18 years were included. One study (moderate-quality, n = 100) reported significantly less ED visits for children treated with vitamin D. No other studies examined the primary outcome (ED visits and hospitalizations). There was a reduced risk of asthma exacerbations in children receiving vitamin D (low-quality; RR 0.41, 95% CI 0.27 to 0.63, 3 studies, n = 378). There was no significant effect for asthma symptom scores and lung function. The serum 25(OH)D level was higher in the vitamin D group at the end of the intervention (low-quality; MD 19.66 nmol/L, 95% CI 5.96 nmol/L to 33.37 nmol/L, 5 studies, n = 167).

Limitations

We identified a high degree of clinical diversity (interventions and outcomes) and methodological heterogeneity (sample size and risk of bias) in included trials.

Conclusions and Relevance

Randomized controlled trials provide some low-quality evidence to support vitamin D supplementation for the reduction of asthma exacerbations. Evidence on the benefits of vitamin D supplementation for other asthma-related outcomes in children is either limited or inconclusive. We recommend that future trials focus on patient-relevant outcomes that are comparable across studies, including standardized definitions of asthma exacerbations.     

Regional versus General Anesthesia for Percutaneous Nephrolithotomy: A Meta-Analysis

ObjectiveTo compare the effectiveness and safety of regional anesthesia (RA) and general anesthesia (GA) for percutaneous nephrolithotomy (PNL).ResultsEight randomized controlled trials (RCTs) and six non-randomized controlled trials (nRCTs) involving 2270 patients were included. Patients receiving RA were associated with shorter operative time (−6.22 min; 95%CI, −9.70 to −2.75; p = 0.0005), lower visual analgesic score on the first and third postoperative day (WMD, −2.62; 95%CI, −3.04 to −2.19; p < 0.00001 WMD, −0.38; 95%CI, −0.58 to −0.18; p = 0.0002), less analgesic requirements (WMD, −59.40 mg; 95%CI, −78.39 to −40.40; p<0.00001), shorter hospitalization (WMD, −0.36d; 95%CI, −0.66 to −0.05; p = 0.02), less blood transfusion (RR, 0.61; 95%CI, 0.41 to 0.93; p = 0.02), fewer modified Clavion-Dindo Grade II (RR, 0.56; 95%CI, 0.37 to 0.83; p = 0.005), Grade III or above postoperative complications (RR, 0.51; 95%CI, 0.33 to 0.77; p = 0.001), and potential benefits of less fever (RR, 0.79; 95%CI, 0.61 to 1.02; p = 0.07), nausea or vomiting (RR, 0.54; 95%CI, 0.20 to 1.46; p = 0.23), whereas more intraoperative hypotension (RR, 3.13; 95%CI, 1.76 to 5.59; p = 0.0001) when compared with patients receiving GA. When nRCTs were excluded, most of the results were stable but the significant differences were no longer detectable in blood transfusion, Grade II and more severe complications. No significant difference in the total postoperative complications and stone-free rate were found.ConclusionsCurrent evidence suggests that both RA and GA can provide safe and effective anesthesia for PNL in carefully evaluated and selected patients. Each anesthesia technique has its own advantages but some aspects still remain unclear and need to be explored in future studies.     

Robotic versus Open Gastrectomy for Gastric Cancer: A Meta-Analysis

Aim

To evaluate the safety and efficacy of robotic gastrectomy versus open gastrectomy for gastric cancer.

Methods

A comprehensive search of PubMed, EMBASE, Cochrane Library, and Web of Knowledge was performed. Systematic review was carried out to identify studies comparing robotic gastrectomy and open gastrectomy in gastric cancer. Intraoperative and postoperative outcomes were also analyzed to evaluate the safety and efficacy of the surgery. A fixed effects model or a random effects model was utilized according to the heterogeneity.

Results

Four studies involving 5780 patients with 520 (9.00%) cases of robotic gastrectomy and 5260 (91.00%) cases of open gastrectomy were included in this meta-analysis. Compared to open gastrectomy, robotic gastrectomy has a significantly longer operation time (weighted mean differences (WMD) =92.37, 95% confidence interval (CI): 55.63 to 129.12, P<0.00001), lower blood loss (WMD: -126.08, 95% CI: -189.02 to -63.13, P<0.0001), and shorter hospital stay (WMD = -2.87; 95% CI: -4.17 to -1.56; P<0.0001). No statistical difference was noted based on the rate of overall postoperative complication, wound infection, bleeding, number of harvested lymph nodes, anastomotic leakage and postoperative mortality rate.

Conclusions

The results of this meta-analysis suggest that robotic gastrectomy is a better alternative technique to open gastrectomy for gastric cancer. However, more prospective, well-designed, multicenter, randomized controlled trials are necessary to further evaluate the safety and efficacy as well as the long-term outcome.     

Physical Activity and Asthma: A Systematic Review and Meta-Analysis

Introduction

This review aims to give an overview of available published evidence concerning the association between physical activity and asthma in children, adolescents and adults.

Methods

We included all original articles in which both physical activity and asthma were assessed in case-control, cross-sectional or longitudinal (cohort) studies. Excluded were studies concerning physical fitness, studies in athletes, therapeutic or rehabilitation intervention studies such as physical training or exercise in asthma patients. Methodological quality of the included articles was assessed according to the Newcastle-Ottawa Scale (NOS).

Results

A literature search was performed until June 2011 and resulted in 6,951 publications derived from PubMed and 1,978 publications from EMBASE. In total, 39 studies met the inclusion criteria: 5 longitudinal studies (total number of subjects n = 85,117) with physical activity at baseline as exposure, and asthma incidence as outcome. Thirty-four cross-sectional studies (n = 661,222) were included. Pooling of the longitudinal studies showed that subjects with higher physical activity levels had lower incidence of asthma (odds ratio 0.88 (95% CI: 0.77–1.01)). When restricting pooling to the 4 prospective studies with moderate to good study quality (defined as NOS≥5) the pooled odds ratio only changed slightly (0.87 (95% CI: 0.77–0.99)). In the cross-sectional studies, due to large clinical variability and heterogeneity, further statistical analysis was not possible.

Conclusions

The available evidence indicates that physical activity is a possible protective factor against asthma development. The heterogeneity suggests that possible relevant effects remain hidden in critical age periods, sex differences, or extremes of levels of physical activity (e.g. sedentary). Future longitudinal studies should address these issues.     

Low Carbohydrate versus Isoenergetic Balanced Diets for Reducing Weight and Cardiovascular Risk: A Systematic Review and Meta-Analysis

Background

Some popular weight loss diets restricting carbohydrates (CHO) claim to be more effective, and have additional health benefits in preventing cardiovascular disease compared to balanced weight loss diets.

Methods and Findings

We compared the effects of low CHO and isoenergetic balanced weight loss diets in overweight and obese adults assessed in randomised controlled trials (minimum follow-up of 12 weeks), and summarised the effects on weight, as well as cardiovascular and diabetes risk. Dietary criteria were derived from existing macronutrient recommendations. We searched Medline, EMBASE and CENTRAL (19 March 2014). Analysis was stratified by outcomes at 3–6 months and 1–2 years, and participants with diabetes were analysed separately. We evaluated dietary adherence and used GRADE to assess the quality of evidence. We calculated mean differences (MD) and performed random-effects meta-analysis. Nineteen trials were included (n = 3209); 3 had adequate allocation concealment. In non-diabetic participants, our analysis showed little or no difference in mean weight loss in the two groups at 3–6 months (MD 0.74 kg, 95%CI −1.49 to 0.01 kg; I² = 53%; n = 1745, 14 trials; moderate quality evidence) and 1–2 years (MD 0.48 kg, 95%CI −1.44 kg to 0.49 kg; I² = 12%; n = 1025; 7 trials, moderate quality evidence). Furthermore, little or no difference was detected at 3–6 months and 1–2 years for blood pressure, LDL, HDL and total cholesterol, triglycerides and fasting blood glucose (>914 participants). In diabetic participants, findings showed a similar pattern.

Conclusions

Trials show weight loss in the short-term irrespective of whether the diet is low CHO or balanced. There is probably little or no difference in weight loss and changes in cardiovascular risk factors up to two years of follow-up when overweight and obese adults, with or without type 2 diabetes, are randomised to low CHO diets and isoenergetic balanced weight loss diets.     

Hypertension and Risk of Cataract: A Meta-Analysis

Background

Cataract is the major cause of blindness across the world. Many epidemiologic studies indicated that hypertension might play an important role in the development of cataract, while others not. We therefore conducted this meta-analysis to determine the relationship between risk of cataract and hypertension.

Methods

Retrieved studies on the association of hypertension with cataract risk were collected from PubMed, Web of Science and the Cochrane Library during June 2014 and were included into the final analysis according to the definite inclusion criteria. Odds ratio (OR) or risk ratio (RR) were pooled with 95% confidence interval (CI) to evaluate the relationship between hypertension and cataract risk. Subgroup analyses were carried out on the basis of cataract type, race and whether studies were adjusted for main components of metabolic syndrome (MS).

Results

The final meta-analysis included 25 studies (9 cohort, 5 case-control and 11 cross-sectional) from 23 articles. The pooled results showed that cataract risk in populations with hypertension significantly increased among cohort studies (RR 1.08; 95% CI: 1.05–1.12) and case-control or cross-sectional studies (OR 1.28; 95% CI: 1.12–1.45). This association was proved to be true among both Mongolians and Caucasians, and the significance was not altered by the adjustment of main components of MS. Subgroup analysis on cataract types indicated that an increased incidence of posterior subcapsular cataract (PSC) resulted among cohort studies (RR 1.22; 95% CI: 1.03–1.46) and cross-sectional/case-control studies (OR 1.23; 95% CI: 1.09–1.39). No association of hypertension with risk of nuclear cataract was found.

Conclusions

The present meta-analysis suggests that hypertension increases the risk of cataract, especially PSC. Further efforts should be made to explore the potential biological mechanisms.     

Maternal Diabetes and Cognitive Performance in the Offspring: A Systematic Review and Meta-Analysis

Objective

Diabetes during gestation is one of the most common pregnancy complications associated with adverse health effects for the mother and the child. Maternal diabetes has been proposed to negatively affect the cognitive abilities of the child, but experimental research assessing its impact is conflicting. The main aim of our study was to compare the cognitive function in children of diabetic and healthy pregnant women.

Methods

A systematic review and meta-analysis was conducted through a literature search using different electronic databases from the index date to January 31, 2015. We included studies that assessed the cognitive abilities in children (up to 14 years) of diabetic and non-diabetic mothers using standardized and validated neuropsychological tests.

Results

Of 7,698 references reviewed, 12 studies involving 6,140 infants met our inclusion criteria and contributed to meta-analysis. A random effect model was used to compute the standardized mean differences and 95% confidence interval (CI) were calculated. Infants (1–2 years) of diabetic mothers had significantly lower scores of mental and psychomotor development compared to control infants. The effect size for mental development was -0.41 (95% CI -0.59, -0.24; p<0.0001) and for psychomotor development was -0.31 (95% CI -0.55, -0.07; p = 0.0125) with non-significant heterogeneity. Diabetes during pregnancy could be associated with decreased intelligence quotient scores in school-age children, although studies showed significant heterogeneity.

Conclusion

The association between maternal diabetes and deleterious effects on mental/psychomotor development and overall intellectual function in the offspring must be taken with caution. Results are based on observational cohorts and a direct causal influence of intrauterine hyperglycemia remains uncertain. Therefore, more trials that include larger populations are warranted to elucidate whether gestational diabetes mellitus (GDM) has a negative impact on offspring central nervous system (CNS).     

Effect of Postpartum Exercise on Mothers and their Offspring: A Review of the Literature

Epidemiological studies suggest that childbearing may contribute to the development of obesity. In the past 12 years, several cross‐sectional and randomized trials have addressed the effect of postpartum exercise on weight loss and/or energy balance in mostly lactating women. These studies suggest that moderate exercise without specific calorie restriction does not promote greater weight or fat loss. This may be because exercise may promote greater energy intake and/or reduced energy expenditure from nonexercise physical activity (thus preventing negative energy balance), but further research is needed. Regular exercise, however, is likely to have other important health benefits after childbirth. A few published studies suggest that postpartum exercise improves aerobic fitness, high‐density lipoprotein‐cholesterol levels, and insulin sensitivity. Exercise may also enhance psychological well‐being, but controlled clinical studies are needed. Although two published studies have addressed whether exercise training attenuates lactation‐induced bone loss, better controlled studies are needed to determine whether postpartum weight‐bearing exercise can improve bone mineral density in lactating and nonlactating women alike. In lactating women, several studies have collectively determined that neither acute nor regular exercise has adverse effects on a mother's ability to successfully breast‐feed. It needs to be determined whether a woman's participation in regular exercise after childbirth will improve her ability to mother or instill lifetime habits of regular physical activity in either herself or her offspring. Overall, published studies have established the importance of regular exercise during the postpartum period. More research, however, is needed in this important area.     

Social Cognition in Individuals at Ultra-High Risk for Psychosis: A Meta-Analysis

Objective

Treatment in the ultra-high risk stage for a psychotic episode is critical to the course of symptoms. Markers for the development of psychosis have been studied, to optimize the detection of people at risk of psychosis. One possible marker for the transition to psychosis is social cognition. To estimate effect sizes for social cognition based on a quantitative integration of the published evidence, we conducted a meta-analysis of social cognitive performance in people at ultra high risk (UHR).

Methods

A literature search (1970-July 2015) was performed in PubMed, PsychINFO, Medline, Embase, and ISI Web of Science, using the search terms ‘social cognition’, ‘theory of mind’, ‘emotion recognition’, ‘attributional style’, ‘social knowledge’, ‘social perception’, ‘empathy’, ‘at risk mental state’, ‘clinical high risk’, ‘psychosis prodrome’, and ‘ultra high risk’. The pooled effect size (Cohen’s D) and the effect sizes for each domain of social cognition were calculated. A random effects model with 95% confidence intervals was used.

Results

Seventeen studies were included in the analysis. The overall significant effect was of medium magnitude (d = 0.52, 95% Cl = 0.38–0.65). No moderator effects were found for age, gender and sample size. Sub-analyses demonstrated that individuals in the UHR phase show significant moderate deficits in affect recognition and affect discrimination in faces as well as in voices and in verbal Theory of Mind (TOM). Due to an insufficient amount of studies, we did not calculate an effect size for attributional bias and social perception/ knowledge. A majority of studies did not find a correlation between social cognition deficits and transition to psychosis, which may suggest that social cognition in general is not a useful marker for the development of psychosis. However some studies suggest the possible predictive value of verbal TOM and the recognition of specific emotions in faces for the transition into psychosis. More research is needed on these subjects.

Conclusion

The published literature indicates consistent general impairments in social cognition in people in the UHR phase, but only very specific impairments seem to predict transition to psychosis.     

Vitamin A Intake and Risk of Melanoma: A Meta-Analysis

Background

Mounting evidence from experimental and animal studies suggests that vitamin A may have a protective effect on melanoma, but the findings on the association of vitamin A intake with risk of melanoma have been inconsistently reported in epidemiologic studies. We attempted to elucidate the association by performing a meta-analysis.

Methods

Eligible studies were identified by searching PubMed and EMBASE databases, as well as by reviewing the references of retrieved publications. Summary odds ratios (OR) with corresponding 95% confidence interval (CI) were computed with a random-effects model. Study-specific ORs and 95% CIs for the highest vs. lowest categories of vitamin A intake were pooled.

Results

A total of 8 case-control studies and 2 prospective studies comprising 3,328 melanoma cases and 233,295 non-case subjects were included. The summary OR for the highest compared with the lowest intake of total vitamin A, retinol and beta-carotene was 0.86 (95% CI = 0.59–1.25), 0.80 (95% CI = 0.69–0.92) and 0.87 (95%CI = 0.62–1.20), respectively. Significant heterogeneity was observed among studies on vitamin A and beta-carotene intake, but not among studies on retinol intake. Subgroup and sensitivity analyses confirmed these findings. There was no indication of publication bias.

Conclusion

Findings from this meta-analysis suggest that intake of retinol, rather than of total vitamin A or beta-carotene, is significantly associated with reduced risk of melanoma.     

Bisphosphonates and Risk of Cardiovascular Events: A Meta-Analysis

Background and Objectives

Some evidence suggests that bisphosphonates may reduce atherosclerosis, while concerns have been raised about atrial fibrillation. We conducted a meta-analysis to determine the effects of bisphosphonates on total adverse cardiovascular (CV) events, atrial fibrillation, myocardial infarction (MI), stroke, and CV death in adults with or at risk for low bone mass.

Methods

A systematic search of MEDLINE and EMBASE through July 2014 identified 58 randomized controlled trials with longer than 6 months in duration that reported CV events. Absolute risks and the Mantel-Haenszel fixed-effects odds ratios (ORs) and 95% confidence intervals (CIs) of total CV events, atrial fibrillation, MI, stroke, and CV death were estimated. Subgroup analyses by follow-up duration, population characteristics, bisphosphonate types, and route were performed.

Results

Absolute risks over 25–36 months in bisphosphonate-treated versus control patients were 6.5% versus 6.2% for total CV events; 1.4% versus 1.5% for atrial fibrillation; 1.0% versus 1.2% for MI; 1.6% versus 1.9% for stroke; and 1.5% versus 1.4% for CV death. Bisphosphonate treatment up to 36 months did not have any significant effects on total CV events (14 trials; ORs [95% CI]: 0.98 [0.84–1.14]; I² = 0.0%), atrial fibrillation (41 trials; 1.08 [0.92–1.25]; I² = 0.0%), MI (10 trials; 0.96 [0.69–1.34]; I² = 0.0%), stroke (10 trials; 0.99 [0.82–1.19]; I² = 5.8%), and CV death (14 trials; 0.88 [0.72–1.07]; I² = 0.0%) with little between-study heterogeneity. The risk of atrial fibrillation appears to be modestly elevated for zoledronic acid (6 trials; 1.24 [0.96–1.61]; I² = 0.0%), not for oral bisphosphonates (26 trials; 1.02 [0.83–1.24]; I² = 0.0%). The CV effects did not vary by subgroups or study quality.

Conclusions

Bisphosphonates do not have beneficial or harmful effects on atherosclerotic CV events, but zoledronic acid may modestly increase the risk of atrial fibrillation. Given the large reduction in fractures with bisphosphonates, changes in osteoporosis treatment decision due to CV risk are not justified.     

Gap Arthroplasty versus Interpositional Arthroplasty for Temporomandibular Joint Ankylosis: A Meta-Analysis

Gap arthroplasty (GA) and interpositional arthroplasty (IA) are widely used for the treatment of temporomandibular joint ankylosis (TMJA). However, controversy remains as to whether IA is superior to GA. PubMed, EMBASE, the Cochrane Library, the Web of science and the China National Knowledge Infrastructure were searched for literature regarding these procedures (published from 1946 to July 28, 2014). A study was included in this analysis if it was: (1) a randomized controlled trial or non-randomized observational cohort study; (2) comparing the clinical outcomes between GA and IA with respect to the maximal incisal opening (MIO) and reankylosis; (3) with a follow-up period of at least 12 months. The methodological quality of the included studies was evaluated according to the Newcastle-Ottawa Scale Eight non-randomized observational cohort studies with 272 patients were included. All the statistical analyses were performed using the RevMan 5.3 and Stat 12. The pooled analysis showed no significant difference in the incidence of reankylosis between the IA group (13/120) and the GA group (29/163) (RR= 0.67, 95% CI=0.38 to 1.16; Z=1.43, p=0.15). The IA group showed a significantly larger MIO than the GA group (MD=1.96, 95% CI=0.21 to 3.72, Z=2.19, p=0.03, I²=0%). In conclusion, patients with TMJA could benefit more from IA than GA, with a larger MIO and a similar incidence of reankylosis. IA shows to be an adequate option in the treatment of TMJA based on the results of maximal incisal opening.