Body mass index, abdominal fatness and the risk of gallbladder disease

Sex difference of the predictive value of BMI, waist circumference and percentage body fat mass for gallstone disease

Gallstone disease (GSD) represents a significant health burden and is reported to be strongly related to obesity. This study examined the effect of sex on the association of BMI, waist circumference (WC) and percentage body fat mass (%FM) with GSD. We enrolled 15 671 middle-aged Taiwanese adults undergoing a physical check-up at a health examination centre. Multiple logistic regression analysis was conducted to identify the association of BMI, WC and %FM with the presence of GSD. AUC of the receiver-operating characteristic (ROC) curves were calculated for BMI, WC and %FM to compare their respective ability to correctly classify patients with GSD. From our findings, GSD prevalence was 8·1 % in men and 6·3 % in women. The percentage of markedly increased obesity indicators was significantly higher in patients with GSD than in those without GSD. Multivariate analysis showed that all obesity indicators were significant predictors of the presence of GSD in women after adjustment. In men, only BMI and WC were significantly associated with the presence of GSD. In the ROC curve analysis, BMI and WC were the best predictors of GSD risk in women and men, respectively. The obesity indicators better predicted the presence of GSD in women than in men. In conclusion, the best obesity indicator of GSD risk differed by sex. In addition to body weight, fat mass and central obesity were associated with GSD risk in women. In men, central obesity may play a more important role in predicting GSD risk.

Reuniting overnutrition and undernutrition, macronutrients, and micronutrients

Over-nutrition and its late consequences are a dominant theme in medicine today. In addition to the health hazards brought on by over-nutrition, the medical community has recently accumulated a roster of health benefits with obesity, grouped under "obesity paradox." Throughout the world and throughout history until the 20^th century, under-nutrition was a dominant evolutionary force. Under-nutrition brings with it a mix of benefits and detriments that are opposite to and continuous with those of over-nutrition. This continuum yields J-shaped or U-shaped curves relating body mass index to mortality. The overweight have an elevated risk of dying in middle age of degenerative diseases while the underweight are at increased risk of premature death from infectious conditions. Micronutrient deficiencies, major concerns of nutritional science in the 20^th century, are being neglected. This "hidden hunger" is now surprisingly prevalent in all weight groups, even among the overweight. Because micronutrient replacement is safe, inexpensive, and predictably effective, it is now an exceptionally attractive target for therapy across the spectrum of weight and age. Nutrition-related conditions worthy of special attention from caregivers include excess vitamin A, excess vitamin D, and deficiency of magnesium.

Strong associations of nine-point body condition scoring with survival and lifespan in cats

OBJECTIVES

The objective of the study was to investigate the associations of a nine-point body condition score (BCS) with survival time and lifespan in cats.

METHODS

Electronic patient records from a cat-dominant primary practice in metropolitan Sydney, Australia, where the body condition of cats was regularly recorded using a nine-point BCS scale were obtained. The maximum BCS of each cat during the visits was used as the primary exposure variable. Two survival analyses were conducted to evaluate the associations of BCS with cats' survival and lifespan.

RESULTS

In total, 2609 cats met the selection criteria from 4020 cats screened. The median of the maximum BCS was 6 (interquartile range [IQR] 5-7). Compared with cats with a maximum BCS of 6, increased hazards of death were observed in cats with a maximum BCS of 3 (hazard ratio [HR] 4.67, 95% confidence interval [CI] 3.00-7.27), 4 (HR 2.61, 95% CI 1.95-3.49), 5 (HR 1.43, 95% CI 11.5-1.76) and 9 (HR 1.80, 95% CI 1.11-2.93). Median lifespan was 15.8 (IQR 13.5-17.6) years. Compared with cats reaching a maximum BCS of 6 in the same age group, cats reaching a maximum BCS of 4 (HR 4.15, 95% CI 1.26-13.67) or 5 (HR 1.75, 95% CI 1.07-2.85) between age 1 and 3 years, and a maximum BCS of 3 (HR 6.09, 95% CI 1.47-25.25) and 9 (HR 2.27, 95% CI 1.27-4.04) between the age of 3 and 11 years had shorter lifespans.

CONCLUSIONS AND RELEVANCE

There are significant associations of nine-point body condition scoring with survival and lifespan, and BCSs <5 and of 9 were found to be negatively associated with both. The study yielded information regarding a desirable BCS for cat longevity that veterinarians could consult with.

Body fatness, diabetes, physical activity and risk of kidney stones: a systematic review and meta-analysis of cohort studies

We conducted a systematic review and meta-analysis to clarify the association between adiposity, diabetes, and physical activity and the risk of kidney stones. PubMed and Embase were searched up to April 22nd 2018 for relevant studies. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random effects models. Thirteen cohort studies were included. The summary relative risk was 1.21 (95% CI 1.12-1.30, I2 = 76%, n = 8) per 5 unit increment in BMI, 1.16 (95% CI 1.12-1.19, I2 = 0%, n = 5) per 10 cm increase in waist circumference, 1.06 (95% CI 1.04-1.08, I2 = 67%, n = 3) per 5 kg increase in weight and 1.12 (95% CI 1.06-1.18, I2 = 86%, n = 3) per 5 kg of weight gain. The summary RR was 1.16 (95% CI 1.03-1.31, I2 = 51%, n = 10) for participants with diabetes compared to participants without diabetes, and 0.93 (95% CI 0.78-1.10, I2 = 80%, n = 4) for high vs. low physical activity. These results suggest a positive association between adiposity and diabetes and the risk of kidney stones, but no association with physical activity.

Distribution of the ATP-binding cassette transporter ABCG8 IVS1-2A>G genotype and clinical characteristics of gallbladder patients in Northeastern Mexico: A pilot study

Biliary lithiasis is a multifactorial pathology determined by the interaction of genes and the environment, characterized by alterations in cholesterol homeostasis and in the metabolism of bile salts. A number of gene polymorphisms and mutations have been identified in the ATP-dependent cholesterol transporter (ABCG8) associated with lithiasis disease. The aim of the present study was to evaluate the association of the ABCG8 gene mutation IVS1-2A>G with cholecystolithiasis in patients from Northeast Mexico. This was a pilot study including 90 Mexican subjects diagnosed by ultrasonography, 57.8% of which presented gallstones. The studied parameters included: Lipid profile, total protein in plasma and polymerase chain reaction-restriction fragment length polymorphism genotyping. Significant differences were identified in total plasma protein, weight and BMI values, with these being these higher in subjects with gallstones (P<0.05). The presence of the mutant allele IVS1-2G was not detected, and the IVS1-2A wild-type allele was present in 100% of the population. Therefore, no association was apparent between the presence of the splice site mutation in ABCG8 (IVS1-2A>G) and the presence of gallstones in the evaluated subjects.

Associations of body condition score with health conditions related to overweight and obesity in cats

OBJECTIVES

To explore the associations of cat body condition score with various health conditions, such as diabetes mellitus, dermatological conditions and hypertension, that have been shown to relate to overweight and/or obesity in cats, dogs or humans.

MATERIALS AND METHODS

Electronic patient records between January 3, 2005 and June 21, 2015 were obtained from a cat-focused primary accession clinic in metropolitan Sydney where the body condition score of cats was routinely evaluated. Binomial logistic regression modelling was conducted to investigate the associations, after adjusting for age, sex and breed, between 21 health conditions and body condition score recorded on a 9-point scale.

RESULTS

Fourteen of the 21 health conditions examined showed significant associations with an increased body condition score, particularly those of 7 and above. These were dermatological conditions, atopic dermatitis, musculoskeletal conditions, arthritis, hypertension, respiratory conditions, asthma, oral conditions, diarrhoea, general and lower urinary tract conditions, ophthalmic conditions, diabetes mellitus and allergic conditions. Additionally, cats with body condition score of 8 or 9 had significantly higher odds for gastrointestinal conditions and upper urinary tract conditions when compared with cats with body condition score of 5.

CLINICAL SIGNIFICANCE

As far as we know, this is the first study reporting positive associations of high body condition score with atopic dermatitis, hypertension, asthma, diarrhoea, ophthalmic conditions and allergic conditions in cats. A large number of positive associations between health conditions and high body condition score indicates that excess fat mass should be given a greater emphasis in preventive health care for cats.

Complications of obesity

Global obesity rates have increased exponentially in recent decades. People are becoming obese younger, morbid obesity is increasing and the full health implications are only beginning to be seen. This article discusses the latest epidemiological data on obesity in adults and children, and systemically reviews the complications associated with the condition.

Frequency of gallstones and mean BMI in decompensated cirrhosis

Introduction

The aim of the study was to determine the frequency of gallstones in patients with decompensated cirrhosis and to know about mean Body mass index (BMI) in patients of decompensated cirrhosis i.e End stage liver disease (ESLD) with and without gallstones.

Methods

it is a cross sectional descriptive study, conducted at the department of Hepato-gastroenterology, Sindh Institute of Urology and Transplantation (SIUT), Karachi from 1^st August 2014 to 28 February 2015. Two hundred patients were enrolled from outpatient clinics of Hepato-gastroenterology that fulfilled the defined selection criteria. Questionnaire was filled for data collection. SPSS version 20.0 was used to analyze data. Mean value of age and BMI was calculated by mean ± S.D. values. Mean ± SD was also calculated for BMI in patients with and without gallstones. Stratification of the age, gender, and liver disease severity were done and chi-Square test was applied. p-values less than 0.05 considered statistically significant.

Results

Two hundred consecutive patients were enrolled among them 112(56%) were male. Mean age was 46.89 ± 11.9, BMI 23.59 ± 4.7 and CTP score was 9.7 ± 1.9. Most of the patient had Child class 'B' cirrhosis 102(51%), most common etiology was found to be Hepatitis C 133 (66.5%), cholelithiasis was found in 59(29.5%), sludge in 36 (18%) and both stone and sludge in 24(12%) of the cases. Advanced liver disease that is, more CTP score and child class 'C' was associated with increased frequency of gall stone formation (p-value = 0.012), and advancing age on age stratification (p-value = 0.024) however no relation was observed with increase BMI, gender, ethnicity, cause or duration of disease in this population.

Conclusion

Gallstone formation is associated with advanced stage of cirrhosis and hepatitis C Virus related CLD, contrary to the established risk factors, no relation of gender or BMI was found in decompensated liver disease.

Pancreatic function following post-endoscopic retrograde cholangiopancreatography pancreatitis: A controlled cohort study with long-term follow-up

Background

Acute pancreatitis is one of the most common causes of gastrointestinal-related hospitalization and the incidence is increasing. Endo- and exocrine pancreatic function can be compromised after acute pancreatitis.

Objective

The purpose of this study was to explore the long-term consequences of post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP) on pancreatic function.

Methods

A follow-up study was carried out with prospective assessment of endo- and exocrine pancreatic function among cases with previous PEP and matched controls from a Danish cohort consisting of 772 patients undergoing first-time ERCP. Pancreatic function was evaluated by faecal-elastase-1 test, blood levels of haemoglobin A1c, C-peptide, vitamin B12, vitamin D and indirectly by changes in body weight.

Results

Twenty-nine cases and 49 controls participated in the study. Mean follow-up time (standard deviation) was 58 (21) months. Twelve (41%), eight (28%) and nine (31%) patients had mild, moderate and severe PEP, respectively. There was no difference between cases and controls with regard to pancreatic function parameters and PEP severity was not associated with pancreatic function. Factors associated with pancreatic function impairment included body mass index, alcohol consumption, age and smoking.

Conclusion

This study suggests that long-term pancreatic function following PEP is similar to the pancreatic function of other patients with comparable gallstone-related morbidity.

Skinfold thickness measurements and mortality in white males during 27.7 years of follow-up

INTRODUCTION

Obesity is a major risk factor for mortality from a range of causes. We investigated whether skinfold measurements were associated with mortality independently of variation in body mass index (BMI).

METHODS

A prospective analysis of mortality in 870 apparently healthy adult Caucasian men participating in an occupational health cohort was undertaken. At baseline, skinfold measurements were taken at biceps, triceps, iliac and subscapular sites. Derived measurements included the sum of all four skinfolds and subscapular to triceps, subscapular to iliac and BMI to iliac ratios. All-cause mortality was analysed by Cox proportional hazards modelling and death in specific mortality subcategories by competing risks analysis.

RESULTS

During a mean of 27.7 years follow up, there were 303 deaths (119 cancer, 101 arteriovascular, 40 infection, 43 other). In univariable analysis, BMI was associated with all-cause, cancer, arteriovascular and other mortality and subscapular skinfold with all-cause and arteriovascular mortality. On bivariable analysis, with inclusion of BMI, subscapular skinfold ceased to be a associated with mortality but iliac skinfold emerged as strongly, negatively associated with all-cause and arteriovascular mortality. In multivariable analysis, with inclusion of age, BMI, smoking, alcohol and exercise, iliac skinfold was negatively associated with all-cause (Hazard ratio HR 0.77, 95% confidence interval CI 0.66-0.90, p = 0.002), arteriovascular (HR 0.75, 95%CI 0.58,0.97, p = 0.02) and infection (HR 0.63, 95%CI 0.42,0.94, p = 0.02) death. Among obese participants (BMI ≥ 30 kg/m²), iliac skinfold of ≤9.7 mm was associated with a six-fold increase in all-cause mortality risk.

CONCLUSION

Low iliac skinfold thickness is an independent risk factor for all-cause mortality in adult white males with risk apparently concentrated among people who are obese.

Metabolic biomarkers and gallstone disease - a population-based study

OBJECTIVES

The objectives for this study were to examine the associations between metabolic biomarkers of obesity including insulin resistance, vascular dysfunction, systemic inflammation, genetic susceptibility and ultrasound proven gallstone disease or cholecystectomy in a population-based cross-sectional study.

MATERIAL AND METHODS

A total of 2650 participants were included, of whom 422 had gallstone disease. Associations between selected metabolic biomarkers and gallstone disease were estimated by multivariable logistic regression models and expressed as odds ratio (OR) and 95% confidence interval (CI).

RESULTS

Gallstone disease was associated with fasting glucose (OR 1.14, 95% CI [1.05;1.24]), fasting insulin (OR 1.03, 95% CI [1.01;1.05]), homeostasis model assessment insulin resistance (OR 1.18, 95% CI [1.02;1.36]), the metabolic syndrome (OR 1.51, 95% CI [1.16;1.96]), white blood cell count (OR 1.07, 95% CI [1.00;1.15]) and C-reactive protein (OR 1.03, 95% CI [1.01;1.05]). A tendency towards an association for soluble urokinase plasminogen activator receptor was also found (OR 1.08, 95% CI [0.99;1.18]). The MC4R(rs17782313) (OR 1.27, 95% CI [1.02;1.58]), MAP2K5(rs2241423) (OR 1.80, 95% CI [1.04;3.41]), NRXN3(rs10146997) (OR 1.26, 95% CI [1.01;1.57]), HHEX(rs1111875) (OR 1.29, 95% CI [1.03;1.62]), FAIM2(rs7138803) (OR 0.66, 95% CI [0.48;0.91]), and apolipoprotein E4 allele (OR 0.76, 95% CI [0.59;0.98]) were associated with gallstone disease. Urinary albumin was not associated with gallstone disease. The association between BMI and gallstone disease was explained by insulin resistance.

CONCLUSIONS

Biomarkers of insulin resistance, systemic inflammation and genetic obesity or type 2 diabetes risk alleles seem to be associated with gallstone disease. Future studies should explore temporal associations and genetic associations in other populations in order to clarify targets for prevention or intervention.

Safety issues with glucagon-like peptide-1 receptor agonists (pancreatitis, pancreatic cancer and cholelithiasis): Data from randomized controlled trials

AIM

Glucagon-like peptide 1 receptor agonists (GLP1-RA) have been associated with an increased risk of pancreatitis and pancreatic cancer. Prior meta-analyses of randomized controlled trials failed to show any significant increase of risk; however, those meta-analyses did not include the recently published cardiovascular outcome trials (CVOT) with GLP1-RA, which provide a substantial additional body of data. The aim of the present meta-analysis is to assess the effect of GLP1-RA on pancreatitis, pancreatic cancers and cholelithiasis.

MATERIALS AND METHODS

A Medline search for GLP-1 receptor agonists (exenatide, liraglutide, lixisenatide, albiglutide, dulaglutide or semaglutide) was performed, collecting all randomized clinical trials with a duration >11 weeks, enrolling patients with type 2 diabetes and comparing a GLP-1 receptor agonist with placebo or any other non-GLP-1 receptor agonist drug.

RESULTS

Of the 113 trials fulfilling inclusion criteria, 13 did not report information on pancreatitis, whereas 72 reported no events in all treatment groups. The incidence of pancreatitis and pancreatic cancer with GLP1-RA was not significantly different from that observed in comparator arms (MH-OR [95% CI] 0.93 [0.65-1.34], P = .71, and 0.94 [0.52-1.70], P = .84, respectively), whereas, a significantly increased risk of cholelithiasis (MH-OR [95% CI] 1.30 [1.01-1.68], P = .041) was detected.

CONCLUSIONS

Presently available data confirm the safety of GLP-1 receptor agonists for pancreatitis. Conversely, therapy with those drugs is associated with an increased risk of cholelithiasis, which deserves further investigation.

The Rotterdam Study: 2018 update on objectives, design and main results

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, otolaryngological, locomotor, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. Since 2016, the cohort is being expanded by persons aged 40 years and over. The findings of the Rotterdam Study have been presented in over 1500 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy ). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.

Body Size Indicators and Risk of Gallbladder Cancer: Pooled Analysis of Individual-Level Data from 19 Prospective Cohort Studies

Background: There are few established risk factors for gallbladder cancer beyond gallstones. Recent studies suggest a higher risk with high body mass index (BMI), an indicator of general heaviness, but evidence from other body size measures is lacking.Methods: Associations of adult BMI, young adult BMI, height, adult weight gain, waist circumference (WC), waist-height ratio (WHtR), hip circumference (HC), and waist-hip ratio (WHR) with gallbladder cancer risk were evaluated. Individual-level data from 1,878,801 participants in 19 prospective cohort studies (14 studies had circumference measures) were harmonized and included in this analysis. Multivariable Cox proportional hazards regression estimated hazard ratios (HR) and 95% confidence intervals (CI).Results: After enrollment, 567 gallbladder cancer cases were identified during 20.1 million person-years of observation, including 361 cases with WC measures. Higher adult BMI (per 5 kg/m2, HR: 1.24; 95% CI, 1.13-1.35), young adult BMI (per 5 kg/m2, HR: 1.12; 95% CI, 1.00-1.26), adult weight gain (per 5 kg, HR: 1.07; 95% CI, 1.02-1.12), height (per 5 cm, HR: 1.10; 95% CI, 1.03-1.17), WC (per 5 cm, HR: 1.09; 95% CI, 1.02-1.17), WHtR (per 0.1 unit, HR: 1.24; 95% CI, 1.00-1.54), and HC (per 5 cm, HR: 1.13; 95% CI, 1.04-1.22), but not WHR (per 0.1 unit, HR: 1.03; 95% CI, 0.87-1.22), were associated with higher risks of gallbladder cancer, and results did not differ meaningfully by sex or other demographic/lifestyle factors.Conclusions: These findings indicate that measures of overall and central excess body weight are associated with higher gallbladder cancer risks.Impact: Excess body weight is an important, and potentially preventable, gallbladder cancer risk factor. Cancer Epidemiol Biomarkers Prev; 26(4); 597-606. ©2017 AACR.

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.

Risk Factors for Gallstone Formation after Surgery for Gastric Cancer

Purpose

The incidence of gallstones after gastrectomy for gastric cancer is higher than in the general population. However, the causes and mechanisms of post-gastrectomy gallstones are unclear. The aim of this study was to evaluate the incidence of gallstone formation and the risk factors for their development after gastrectomy for gastric cancer.

Materials and Methods

Of 1,744 gastric cancer patients who underwent gastrectomy at Seoul National University Bundang Hospital between January 2010 and December 2012, 1,284 were included in this study and retrospectively reviewed. Patients' age, sex, body mass index (BMI), tumor location, stage, type of gastrectomy, type of reconstruction, and extent of node dissection were evaluated.

Results

The incidence of gallstones after gastrectomy for gastric cancer was significantly higher in men than in women (P=0.019). Exclusion of the duodenum during reconstruction was associated with a significantly higher incidence of gallstones (P=0.003). Overweight and obese patients with BMI ≥23 kg/m² had significantly higher incidence of gallstones than those with a lower BMI (P=0.006). Multivariate analysis showed that obesity (hazard ratio, HR=1.614; 95% confidence interval, CI: 1.135~2.296; P=0.008), male sex (HR=1.515, 95% CI: 1.029~2.231, P=0.033), and exclusion of the duodenum (HR=1.648, 95% CI: 1.192~2.280, P=0.003) were significant, independent risk factors for gallstones after gastrectomy.

Conclusions

The cumulative incidence of gallstones for 5 years after gastrectomy was 15.3%. Male sex, obesity, and exclusion of the duodenum were risk factors for gallstone formation after gastrectomy. Careful surveillance will be required for these patient groups after gastrectomy.

BMI and all cause mortality: systematic review and non-linear dose-response meta-analysis of 230 cohort studies with 3.74 million deaths among 30.3 million participants

OBJECTIVE

To conduct a systematic review and meta-analysis of cohort studies of body mass index (BMI) and the risk of all cause mortality, and to clarify the shape and the nadir of the dose-response curve, and the influence on the results of confounding from smoking, weight loss associated with disease, and preclinical disease.

DATA SOURCES

PubMed and Embase databases searched up to 23 September 2015.

STUDY SELECTION

Cohort studies that reported adjusted risk estimates for at least three categories of BMI in relation to all cause mortality.

DATA SYNTHESIS

Summary relative risks were calculated with random effects models. Non-linear associations were explored with fractional polynomial models.

RESULTS

230 cohort studies (207 publications) were included. The analysis of never smokers included 53 cohort studies (44 risk estimates) with >738 144 deaths and >9 976 077 participants. The analysis of all participants included 228 cohort studies (198 risk estimates) with >3 744 722 deaths among 30 233 329 participants. The summary relative risk for a 5 unit increment in BMI was 1.18 (95% confidence interval 1.15 to 1.21; I(2)=95%, n=44) among never smokers, 1.21 (1.18 to 1.25; I(2)=93%, n=25) among healthy never smokers, 1.27 (1.21 to 1.33; I(2)=89%, n=11) among healthy never smokers with exclusion of early follow-up, and 1.05 (1.04 to 1.07; I(2)=97%, n=198) among all participants. There was a J shaped dose-response relation in never smokers (Pnon-linearity <0.001), and the lowest risk was observed at BMI 23-24 in never smokers, 22-23 in healthy never smokers, and 20-22 in studies of never smokers with ≥20 years' follow-up. In contrast there was a U shaped association between BMI and mortality in analyses with a greater potential for bias including all participants, current, former, or ever smokers, and in studies with a short duration of follow-up (<5 years or <10 years), or with moderate study quality scores.

CONCLUSION

Overweight and obesity is associated with increased risk of all cause mortality and the nadir of the curve was observed at BMI 23-24 among never smokers, 22-23 among healthy never smokers, and 20-22 with longer durations of follow-up. The increased risk of mortality observed in underweight people could at least partly be caused by residual confounding from prediagnostic disease. Lack of exclusion of ever smokers, people with prevalent and preclinical disease, and early follow-up could bias the results towards a more U shaped association.

Gallstones

Gallstones grow inside the gallbladder or biliary tract. These stones can be asymptomatic or symptomatic; only gallstones with symptoms or complications are defined as gallstone disease. Based on their composition, gallstones are classified into cholesterol gallstones, which represent the predominant entity, and bilirubin ('pigment') stones. Black pigment stones can be caused by chronic haemolysis; brown pigment stones typically develop in obstructed and infected bile ducts. For treatment, localization of the gallstones in the biliary tract is more relevant than composition. Overall, up to 20% of adults develop gallstones and >20% of those develop symptoms or complications. Risk factors for gallstones are female sex, age, pregnancy, physical inactivity, obesity and overnutrition. Factors involved in metabolic syndrome increase the risk of developing gallstones and form the basis of primary prevention by lifestyle changes. Common mutations in the hepatic cholesterol transporter ABCG8 confer most of the genetic risk of developing gallstones, which accounts for ∼25% of the total risk. Diagnosis is mainly based on clinical symptoms, abdominal ultrasonography and liver biochemistry tests. Symptoms often precede the onset of the three common and potentially life-threatening complications of gallstones (acute cholecystitis, acute cholangitis and biliary pancreatitis). Although our knowledge on the genetics and pathophysiology of gallstones has expanded recently, current treatment algorithms remain predominantly invasive and are based on surgery. Hence, our future efforts should focus on novel preventive strategies to overcome the onset of gallstones in at-risk patients in particular, but also in the population in general.

Diabetes mellitus and the risk of gallbladder disease: A systematic review and meta-analysis of prospective studies

BACKGROUND

Diabetes has been hypothesized to increase the risk of gallbladder disease based on the observation that obesity and insulin resistance are associated with gallbladder disease. Although several studies have investigated the association between a diabetes diagnosis and risk of gallbladder disease, the results have not been entirely consistent. For this reason we conducted a systematic review and meta-analysis of the available cohort studies.

MATERIALS AND METHODS

We searched the PubMed and Embase databases for studies of diabetes and gallbladder disease (defined as gallstones, cholecystectomy, or cholecystitis) up to January 9th 2015. Prospective studies were included if they reported relative risk estimates and 95% confidence intervals of gallbladder disease associated with a diabetes diagnosis. Summary relative risks were estimated by use of a random effects model.

RESULTS

We identified 10 prospective studies that could be included in the meta-analysis which included 223,651 cases among 7,365,198 participants. The summary RR for diabetes patients was 1.56 (95% CI: 1.26-1.93, I(2)=99.4%, pheterogeneity<0.0001). The results persisted when stratified by gender, and in most subgroup analyses and there was no heterogeneity among studies with more than 10 years duration of follow-up. There was no evidence of publication bias.

CONCLUSIONS

Our analysis provides further support for an increased risk of gallbladder disease among diabetes patients.