Determinants for gallstone formation – a new data cohort study and a systematic review with meta-analysis*

Objective: Only few determinants of gallstone formation have been identified in cohort studies. The aim was to identify further determinants for gallstones in a Danish cohort and to perform a meta-analysis of results from existing cohorts.

Material and methods: Data from a cohort study was used. Gallstone incidence was assessed through repeated ultrasound examinations. Body mass index (BMI), blood pressure, self-rated health, lifestyle variables, blood lipids, and use of female sex hormones were measured at the baseline examination. Statistical analyses included logistic regression. Based on a prospective protocol, a systematic review of the literature was performed identifying all articles dealing with determinants of incident gallstones. Meta-analyses of comparable determinants were performed through fixed effect models.

Results: Participants with no gallstones at baseline and with at least one re-examination were followed-up completely (mean 11.6 years, N?=?2848). The overall cumulative incidence of gallstones was 0.60% per year. Independent positive determinants for incident gallstones were age, female sex, non-high density lipoprotein (non-HDL) cholesterol, and gallbladder polyps. In addition, BMI was positively associated in men. The systematic review additionally identified associations for comorbidities, parity, and dietary factors. Meta-analysis confirmed the significant associations for incident gallstones and age, female sex, BMI, and non-HDL cholesterol. No significant associations were found for blood pressure, smoking, alcohol consumption, HDL cholesterol, or triglycerides in meta-analyses.

Conclusions: Age, female sex, BMI, non-HDL cholesterol, and polyps are independent determinants for gallstone formation. Incident gallstones and the metabolic syndrome share common risk factors. More studies are needed for further exploration.     

Longitudinal physical activity trajectories from childhood to adulthood and their determinants: The Young Finns Study

Determining lifelong physical activity (PA) trajectories and their determinants is essential to promote a physically active lifestyle throughout the life‐course. We aimed to identify PA trajectories from childhood to midlife and their determinants in a longitudinal population‐based cohort. This study is a part of the Cardiovascular Risk in Young Finns Study. From 1980, a population‐based cohort (N = 3596; 1764 boys/1832 girls, age 3‐18 years) has been followed up for 31 years. PA indices were formed based on self‐reported data (between age 9‐49 years) on frequency, duration, and intensity of leisure (during childhood) or high‐intensity (at later age) PA and on sports club participation/competitions. PA trajectories were analyzed using group‐based trajectory modeling. Childhood (age 12 years), young adulthood (age 24 years), and early midlife (age 37 years) determinants were analyzed. Five PA trajectories were identified: persistently active (6.6%), decreasingly active (13.9%), increasingly active (13.5%), persistently low active (51.4%, reference group), persistently inactive (14.6%). In childhood, rural residential area (OR 0.45, 95% CI 0.21‐0.96) and high academic performance (OR 2.18; 95% CI 1.58‐3.00) associated with persistently active group. In early midlife, smoking (OR 1.66; 95% CI 1.07‐2.58) associated with persistently inactive group, regular alcohol drinking (OR 2.91; 95% CI 1.12‐7.55) with persistently active group and having children (OR 2.07; 95% CI 1.27‐3.38) with decreasingly active group. High adulthood education associated with both decreasingly (OR 1.87; 95% CI 1.05‐3.35) and increasingly (OR 2.09; 95% CI 1.19‐3.68) active groups. We identified five PA trajectories from childhood into midlife. Most prominent determinants were academic achievement, education, having children and health habits (i.e. smoking/alcohol use).