Coffee consumption and risk of pancreatic cancer: a systematic review and dose–response meta-analysis

The association between coffee consumption and pancreatic cancer risk has been extensively studied; however, there is no consistent conclusion. Therefore, this meta-analysis study sought to evaluate dose–response relationship between them. A search was conducted using the PubMed and Web of Science databases. Thirteen high-quality cohort studies were identified, involving in 959,992 study participants and 3831 pancreatic cancer cases. Comparing the highest with lowest categories of coffee intake, the pooled relative risk (RR) was 1.08 (95% CI 0.94–1.25). For dose–response analysis, no evidence of a nonlinear dose–response association between coffee consumption and pancreatic cancer (p for nonlinearity =0.171) was found. The risk of pancreatic cancer was increased by 5.87% (RR =1.06, 95% CI 1.05–1.07) with the increment of one cup/day. Coffee consumption was identified to be related with the increasing risk of pancreatic cancer in a dose–response manner. Nevertheless, further mechanistic studies are needed to clarify the concerned issues.     

Egg consumption and risk of GI neoplasms: dose–response meta-analysis and systematic review

Purpose

Previous epidemiological studies on egg consumption and the risk of gastrointestinal (GI) neoplasms suggest a positive association; however, data are limited and the evidence remains controversial. This study aims to investigate and quantify the potential dose–response relationship with an evaluation of cancer site-specific differences.

Methods

Relevant studies were identified after the literature search via electronic databases until January 2014. Subgroup analysis for serving portions was performed using two standardized classification methods: (1) less than 3, or 3 or more eggs per week; (2) less than 3, 3–5, or more than 5 eggs per week. Method two excludes studies that only reported consumption frequency. Pooled adjusted odds ratios (ORs) comparing highest and lowest categories of dietary pattern scores were calculated using a random-effects model.

Results

Thirty-seven case–control and seven cohort studies were included for meta-analysis, which contained a total of 424,867 participants and 18,852 GI neoplasm cases. The combined odds ratio (OR) was calculated to 1.15 (95 % CI 1.09–1.22; p value heterogeneity <0.001), showing only a slight increase in risk. The correlation was stronger for colon cancers 1.29 (95 % CI 1.14–1.46; p value heterogeneity <0.22). Dose–response analysis revealed similar results with stratification methods, and the ORs for an intake of <3 and ≥3 eggs per week were 1.14 (95 % CI 1.07–1.22; p value heterogeneity = 0.38) and 1.25 (95 % CI 1.14–1.38; p value heterogeneity = 0.25), respectively. With method 2, the ORs for an intake of <3, 3–5, and >5 eggs per week were 1.13 (95 % CI 1.06–1.21; p value heterogeneity = 0.25), 1.14 (95 % CI 1.01–1.29; p value heterogeneity = 0.06), and 1.19 (95 % CI 1.01–1.39; p value heterogeneity <0.001), respectively.

Conclusion

This study provides evidence that egg consumption is associated with a positive dose–response association with the development of GI neoplasms.     

Alcohol consumption and dementia risk: a dose–response meta-analysis of prospective studies

It is widely believed that light-to-moderate alcohol intake may protect against dementia while excessive drinking may instead increase the risk. Nonetheless, these findings need cautious interpretations due to varying methodologies and lack of standard definition, which hindered our transferring into preventative practice. The objective of this study is to investigate the potential dose–response association between alcohol consumption and risk of dementia. A systematic search was conducted in electronic databases to identify relevant studies. Risk estimates were combined using a random-effect model. Eleven studies with 73,330 participants and 4586 cases for all-cause dementia (ACD), five studies with 52,715 participants and 1267 cases for Alzheimer’s dementia (AD) and four studies with 49,535 participants and 542 cases for vascular dementia were included. We observed a nonlinear association between alcohol consumption and ACD risk (p _nonlinearity < 0.05). The alcohol dose associated with lower risk of dementia was confined to at most 12.5 g/day, with the risk hitting bottom (RR ≈ 0.9) at roughly 6 g/day. Of note, the ACD risk seemed to be elevated (≈10%) when the dose surpasses certain levels: 23 drinks/week or 38 g/day. For the alcohol type, recommendation for wine is prioritized. The subgroup analysis further indicated that the effect of alcohol may be greater in younger adults (<60 years old) with regard to fighting against dementia. Modest alcohol consumption (≤12.5 g/day) is associated with a reduced risk of dementia with 6 g/day of alcohol conferring a lower risk than other levels while excessive drinking (≥38 g/day) may instead elevate the risk.     

Physical activity and the risk of heart failure: a systematic review and dose–response meta-analysis of prospective studies

European Journal of Epidemiology - Although physical activity is an established protective factor for cardiovascular diseases such as ischemic heart disease and stroke, less is known with regard to...     

Caffeine intake during pregnancy and adverse birth outcomes: a systematic review and dose–response meta-analysis

Caffeine is commonly consumed during pregnancy, crosses the placenta, with fetal serum concentrations similar to the mother’s, but studies of birth outcome show conflicting findings. We systematically searched Medline and Embase for relevant publications. We conducted meta-analysis of dose–response curves for associations between caffeine intake and spontaneous abortion, stillbirth, preterm delivery, low birth weight and small for gestational age (SGA) infants. Meta-analyses included 60 unique publications from 53 cohort and case–control studies. An increment of 100 g caffeine was associated with a 14 % (95 % CI 10–19 %) increase in risk of spontaneous abortion, 19 % (5–35 %) stillbirth, 2 % (?2 to 6 %) preterm delivery, 7 % (1–12 %) low birth weight, and 10 % (95 % CI 6–14 %) SGA. There was substantial heterogeneity in all models, partly explained by adjustment for smoking and previous obstetric history, but not by prospective assessment of caffeine intake. There was evidence of small-study effects such as publication bias. Greater caffeine intake is associated with an increase in spontaneous abortion, stillbirth, low birth weight, and SGA, but not preterm delivery. There is no identifiable threshold below which the associations are not apparent, but the size of the associations are generally modest within the range of usual intake and are potentially explained by bias in study design or publication. There is therefore insufficient evidence to support further reductions in the maximum recommended intake of caffeine, but maintenance of current recommendations is a wise precaution.     

Physical activity and the risk of gestational diabetes mellitus: a systematic review and dose–response meta-analysis of epidemiological studies

Physical activity has been inconsistently associated with risk of gestational diabetes mellitus in epidemiological studies, and questions remain about the strength and shape of the dose–response relationship between the two. We therefore conducted a systematic review and meta-analysis of cohort studies and randomized trials on physical activity and gestational diabetes mellitus. PubMed, Embase and Ovid databases were searched for cohort studies, and randomized controlled trials of physical activity and risk of gestational diabetes mellitus, up to August 5th 2015. Summary relative risks (RRs) were estimated using a random effects model. Twenty-five studies (26 publications) were included. For total physical activity the summary RR for high versus low activity was 0.62 (95 % CI 0.41–0.94, I² = 0 %, n = 4) before pregnancy, and 0.66 (95 % CI 0.36–1.21, I² = 0 %, n = 3) during pregnancy. For leisure-time physical activity the respective summary RRs for high versus low activity was 0.78 (95 % CI 0.61–1.00, I² = 47 %, n = 8) before pregnancy, and it was 0.80 (95 % CI 0.64–1.00, I² = 17 %, n = 17) during pregnancy. The summary RR for pre-pregnancy activity was 0.70 (95 % CI 0.49–1.01, I² = 72.6 %, n = 3) per increment of 5 h/week and for activity during pregnancy was 0.98 (95 % CI 0.87–1.09, I² = 0 %, n = 3) per 5 h/week. There was evidence of a nonlinear association between physical activity before pregnancy and the risk of gestational diabetes mellitus, p_nonlinearity = 0.005, with a slightly steeper association at lower levels of activity although further reductions in risk were observed up to 10 h/week. There was also evidence of nonlinearity for physical activity in early pregnancy, p_nonlinearity = 0.008, with no further reduction in risk above 8 h/week. There was some indication of inverse associations between walking (before and during pregnancy) and vigorous activity (before pregnancy) and the risk of gestational diabetes mellitus. This meta-analysis suggests that there is a significant inverse association between physical activity before pregnancy and in early pregnancy and the risk of gestational diabetes mellitus. Further studies are needed to clarify the association between specific types and intensities of activity and gestational diabetes mellitus.     

Body mass index,abdominal fatness,and the risk of sudden cardiac death: a systematic review and dose–response meta-analysis of prospective studies

Although overweight and obesity are established risk factors for some types of heart disease including ischemic heart disease, heart failure and atrial fibrillation, less is known about the association between adiposity and sudden cardiac death. We conducted a systematic review and meta-analysis of prospective studies to clarify the association between adiposity and risk of sudden cardiac death. PubMed and Embase databases were searched up to July 20th 2017. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random effects models. The summary RR was 1.16 (95% CI 1.05–1.28, I² = 68%, n = 14) per 5 unit increment in BMI, and 1.82 (95% CI 1.61–2.07, I² = 0%, n = 3) per 0.1 unit increase in waist-to-hip ratio, and 1.03 (95% CI 0.93–1.15, I² = 0%, n = 2) per 10 cm increase in waist circumference. The heterogeneity in the analysis of BMI and sudden cardiac death persisted across most subgroup analyses. The association was stronger among studies with longer follow-up compared to short follow-up and was observed in the European and American studies, but not in the Asian studies. There was a J-shaped association between BMI and sudden cardiac death and the lowest risk was observed in the normal weight range, however, the increased risk with a low BMI was attenuated among studies with a longer duration of follow-up. This meta-analysis suggest an increased risk of sudden cardiac death with increasing BMI and waist-to-hip ratio, however, further studies with stratification for smoking status are needed of waist circumference, weight changes and adiposity at younger ages.     

Body mass index,abdominal fatness,weight gain and the risk of psoriasis: a systematic review and dose–response meta-analysis of prospective studies

Greater body mass index (BMI) has been associated with increased risk of psoriasis in case–control and cross-sectional studies, however, the evidence from prospective studies has been limited. We conducted a systematic review and dose–response meta-analysis of different adiposity measures and the risk of psoriasis to provide a more robust summary of the evidence based on data from prospective studies. PubMed and Embase databases were searched for relevant studies up to August 8th 2017. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using a random effects model. The summary relative risk (RR) for a 5 unit increment in BMI was 1.19 (95% CI 1.10–1.28, I² = 83%, n = 7). The association appeared to be stronger at higher compared to lower levels of BMI, p_nonlinearity < 0.0001, and the lowest risk was observed at a BMI around 20. The summary RR was 1.24 (95% CI 1.17–1.31, I² = 0%, p_{heterogeneity} = 0.72, n = 3) per 10 cm increase in waist circumference, 1.37 (95% CI 1.23–1.53, I² = 0%, p_{heterogeneity} = 0.93, n = 3) per 0.1 unit increase in waist-to-hip ratio, and 1.11 (95% CI 1.07–1.16, I² = 47%, p_{heterogeneity} = 0.15, n = 3) per 5 kg of weight gain. Adiposity as measured by BMI, waist circumference, waist-to-hip ratio, and weight gain is associated with increased risk of psoriasis.     

Body mass index,abdominal fatness,fat mass and the risk of atrial fibrillation: a systematic review and dose–response meta-analysis of prospective studies

Different adiposity measures have been associated with increased risk of atrial fibrillation, however, results have previously only been summarized for BMI. We therefore conducted a systematic review and meta-analysis of prospective studies to clarify the association between different adiposity measures and risk of atrial fibrillation. PubMed and Embase databases were searched up to October 24th 2016. Summary relative risks (RRs) were calculated using random effects models. Twenty-nine unique prospective studies (32 publications) were included. Twenty-five studies (83,006 cases, 2,405,381 participants) were included in the analysis of BMI and atrial fibrillation. The summary RR was 1.28 (95% confidence interval: 1.20–1.38, I² = 97%) per 5 unit increment in BMI, 1.18 (95% CI: 1.12–1.25, I² = 73%, n = 5) and 1.32 (95% CI: 1.16–1.51, I² = 91%, n = 3) per 10 cm increase in waist and hip circumference, respectively, 1.09 (95% CI: 1.02–1.16, I² = 44%, n = 4) per 0.1 unit increase in waist-to-hip ratio, 1.09 (95% CI: 1.02–1.16, I² = 94%, n = 4) per 5 kg increase in fat mass, 1.10 (95% CI: 0.92–1.33, I² = 90%, n = 3) per 10% increase in fat percentage, 1.10 (95% CI: 1.08–1.13, I² = 74%, n = 10) per 5 kg increase in weight, and 1.08 (95% CI: 0.97–1.19, I² = 86%, n = 2) per 5% increase in weight gain. The association between BMI and atrial fibrillation was nonlinear, p _nonlinearity < 0.0001, with a stronger association at higher BMI levels, however, increased risk was observed even at a BMI of 22–24 compared to 20. In conclusion, general and abdominal adiposity and higher body fat mass increase the risk of atrial fibrillation.     

Whole grain and refined grain consumption and the risk of type 2 diabetes: a systematic review and dose–response meta-analysis of cohort studies

Several studies have suggested a protective effect of intake of whole grains, but not refined grains on type 2 diabetes risk, but the dose–response relationship between different types of grains and type 2 diabetes has not been established. We conducted a systematic review and meta-analysis of prospective studies of grain intake and type 2 diabetes. We searched the PubMed database for studies of grain intake and risk of type 2 diabetes, up to June 5th, 2013. Summary relative risks were calculated using a random effects model. Sixteen cohort studies were included in the analyses. The summary relative risk per 3 servings per day was 0.68 (95 % CI 0.58–0.81, I² = 82 %, n = 10) for whole grains and 0.95 (95 % CI 0.88–1.04, I² = 53 %, n = 6) for refined grains. A nonlinear association was observed for whole grains, p _nonlinearity < 0.0001, but not for refined grains, p _nonlinearity = 0.10. Inverse associations were observed for subtypes of whole grains including whole grain bread, whole grain cereals, wheat bran and brown rice, but these results were based on few studies, while white rice was associated with increased risk. Our meta-analysis suggests that a high whole grain intake, but not refined grains, is associated with reduced type 2 diabetes risk. However, a positive association with intake of white rice and inverse associations between several specific types of whole grains and type 2 diabetes warrant further investigations. Our results support public health recommendations to replace refined grains with whole grains and suggest that at least two servings of whole grains per day should be consumed to reduce type 2 diabetes risk.     

Age-specific ALS incidence: a dose–response meta-analysis

To evaluate the association between worldwide ALS incidence rates and age, using a dose–response meta-analysis. We reviewed Medline and Embase up to July 2016 and included all population-based studies of newly-diagnosed cases, using multiple sources for case ascertainment. A dose–response meta-analysis was performed. A meta-regression investigated potential sources of heterogeneity. Of 3254 articles identified in the literature, we included 41 incidence studies covering 42 geographical areas. Overall, the fit between observed and predicted age-specific rates was very good. The expected variation of ALS incidence with age was characterized, in each study, by a progressive increase in the incidence from the 40s leading to a peak in the 60s or 70s, followed by a sharp decrease. Cochran’s Q test suggested a significant heterogeneity between studies. Overall, estimated patterns of ALS age-specific incidence (at which the peak was reached) were similar among subcontinents of Europe and North America: peak of ALS incidence ranged in these areas between 6.98 and 8.17/100,000 PYFU, which referred to age in the range 71.6–77.4 years. The relationship between age and ALS incidence appeared different for Eastern Asia which was characterized by a peak of ALS incidence at 2.20/100,000 PYFU around 75 years of age. This study confirms the consistency of the age-specific ALS incidence pattern within different subcontinents. Age-specific incidence appears lower in Eastern Asia as compared to Europe and North America.     

Folate intake and pancreatic cancer risk: an overall and dose–response meta-analysis

Objective

Inconsistent findings of association between supplemental folate consumption and pancreatic cancer risk have been observed in the literature. This study aims to summarize the relationship between folate intake and risk of pancreatic cancer.

Study design

Pertinent studies published before November 2011 were identified by searching PubMed and Embase and by reviewing the reference lists of retrieved articles. The summary relative risks were estimated by the random effects model. A linear regression analysis of the natural logarithm of the relative risk (RR) was carried out to assess a possible dose–response relationship between folate intake and pancreatic cancer risk.

Results

Ten studies on dietary and supplemental folate intake and pancreatic cancer (4 case–control and 6 cohort studies) were included in the meta-analysis. The pooled RRs of pancreatic cancer for the highest vs lowest categories of dietary folate intake and supplemental folate intake were 0.66 (95% CI: 0.49–0.88) and 1.08 (95% CI, 0.82–1.41), respectively. The dose–response meta-analysis indicated that a 100 μg/day increment in dietary folate intake conferred a RR of 0.93 (95% CI: 0.90–0.97). These findings support the hypothesis that dietary folate may play a protective role in carcinogenesis of pancreatic cancer.     

Parent–child interactions and obesity prevention: a systematic review of the literature

Child obesity research has generally not examined multiple layers of parent–child relationships during weight-related activities such as feeding, eating and play. A literature review was conducted to locate empirical studies that measured parent–child interactions and child eating and child weight variables; five papers met the inclusion criteria and were included in the review. The findings of the review revealed that parent–child relationships are an important element in explaining the unhealthy trend of childhood obesity. We argue that prevention/intervention strategies must extend on the current models of parenting by targeting the family from a bi-directional perspective, and focusing, specifically, on the mutually responsive orientation that exists in the parent–child relationship.     

Dairy foods intake and risk of Parkinson’s disease: a dose–response meta-analysis of prospective cohort studies

Dairy foods have been linked to Parkinson’s disease (PD), and a meta-analysis of prospective cohort studies on dairy foods intake and PD risk was conducted. Eligible studies were identified in a literature search of EMBASE and PubMed up to April 2014. Seven results from prospective studies were included, including 1,083 PD cases among 304,193 subjects. The combined risk of PD for highest vs. lowest level of dairy foods intake was 1.40 (1.20–1.63) overall, 1.66 (1.29–2.14) for men and 1.15 (0.85–1.56) for women. For highest vs. lowest level, the PD risk was 1.45 (1.23–1.73) for milk, 1.26 (0.99–1.60) for cheese, 0.95 (0.76–1.20) for yogurt and 0.76 (0.51–1.13) for butter. The linear dose–response relationship showed that PD risk increased by 17 % [1.17 (1.06–1.30)] for every 200 g/day increment in milk intake (P_{for non-linearity} = 0.22), and 13 % [1.13 (0.91–1.40)] for every 10 g/day increment in cheese intake (P_{for non-linearity} = 0.39). The absolute risk differences were estimated to be 2–4 PD cases per 100,000 person-years for every 200 g/day increment in milk intake, and 1–3 PD cases per 100,000 person-years for every 10 g/day increment in cheese intake. Dairy foods (milk, cheese) might be positively associated with increased risk of PD, especially for men.     

The Troms? heart study: alcoholic beverages and coronary risk factors.

Frequency of beer, wine, and spirits drinking and inebriation by alcohol were associated with serum lipids and blood pressure in 14,667 free-living men and women aged 20 to 54 years. Regression analysis including several background variables revealed that alcohol was more "favourably" associated with coronary risk factors than previously reported, due to the small consumption of alcohol in the population (only 2.0% of men and 0.3% of women reported drinking every day) or to unknown confounding factors: wine (p less than 0.05) and inebriation (p less than 0.01) were inversely related with total cholesterol in women; the strong positive relation with HDL-cholesterol in both sexes previously reported was confirmed; beer (p less than 0.05) and inebriation p(less than 0.05) in men and spirits (p less than 0.01) in women seemed to decrease triglycerides; and a new observation may be the negative association between wine and blood pressure (systolic p less than 0.01 in both sexes) as opposed to the positive relation with beer (p less than 0.01 both pressures in men) and spirits (p less than 0.05 systolic pressure and p less than 0.01 diastolic pressure in men and p less than 0.05 diastolic pressure in women). Women showed more "favourable effects" of alcohol than men, and one reason may be that they drank less often. Wine gave lower risk factor readings than beer, and especially lower than spirits.     

Milk and dairy consumption and risk of cardiovascular diseases and all-cause mortality: dose–response meta-analysis of prospective cohort studies

With a growing number of prospective cohort studies, an updated dose–response meta-analysis of milk and dairy products with all-cause mortality, coronary heart disease (CHD) or cardiovascular disease (CVD) have been conducted. PubMed, Embase and Scopus were searched for articles published up to September 2016. Random-effect meta-analyses with summarised dose–response data were performed for total (high-fat/low-fat) dairy, milk, fermented dairy, cheese and yogurt. Non-linear associations were investigated using the spine models and heterogeneity by subgroup analyses. A total of 29 cohort studies were available for meta-analysis, with 938,465 participants and 93,158 mortality, 28,419 CHD and 25,416 CVD cases. No associations were found for total (high-fat/low-fat) dairy, and milk with the health outcomes of mortality, CHD or CVD. Inverse associations were found between total fermented dairy (included sour milk products, cheese or yogurt; per 20 g/day) with mortality (RR 0.98, 95% CI 0.97–0.99; I² = 94.4%) and CVD risk (RR 0.98, 95% CI 0.97–0.99; I² = 87.5%). Further analyses of individual fermented dairy of cheese and yogurt showed cheese to have a 2% lower risk of CVD (RR 0.98, 95% CI 0.95–1.00; I² = 82.6%) per 10 g/day, but not yogurt. All of these marginally inverse associations of totally fermented dairy and cheese were attenuated in sensitivity analyses by removing one large Swedish study. This meta-analysis combining data from 29 prospective cohort studies demonstrated neutral associations between dairy products and cardiovascular and all-cause mortality. For future studies it is important to investigate in more detail how dairy products can be replaced by other foods.     

Whole-body vibration and low back pain: a systematic, critical review of the epidemiological literature 1992–1999

Objectives: A previous extensive review of the literature including that from the middle of 1992 concluded that whole-body vibrations may contribute to low back pain, but that the exposure-response relationship had not been clarified. We reviewed the literature of the past 7 years to find out: (i) whether there is evidence in the recent epidemiological literature for a causal association between whole-body vibrations and low back pain, and (ii) if there is evidence in the recent literature for a dose-response relationship between whole-body vibrations and low back pain. Methods: All relevant epidemiological articles which were obtained through a search in the databases MEDLINE, OSH-ROM and TOXLINE, and through personal communication, were reviewed independently by the two authors, using a checklist. Results: Twenty-four original articles concerning the association between whole-body vibrations and the lower back were retained for use. The quality of the papers was mostly low, but improved with time. Only seven articles passed our predetermined quality criteria. Of the seven reports, one showed increased frequency of lumbar prolapse in occupational drivers, and six showed low back pain to be more frequent in whole-body vibration-exposed groups. Only two out of the four articles reporting on dose, showed a dose-response association. Conclusions: Despite the lack of definite evidence, we found sufficient reasons for the reduction of whole-body vibration-exposure to the lowest possible level. If new knowledge is to be produced, good prospective studies with repeated measurements of exposure, analyses of work postures, and clear definitions and subgroupings of low back pain are needed. Other research in this field should be given up, and the resources used for more important issues, as the size of the problem of whole body vibration is probably on the decrease because of the technical prophylactic developments that are already in progress. Received: 19 July 1999 / Accepted: 27 December 1999