Dietary Patterns and Hip Fracture Risk in the UK Biobank

Sponsor

University of Leeds (Other)

Overall Status

Active, not recruiting

CT.gov ID

NCT05554549

Collaborator

(none)

500,000

Enrollment

Location

206.9

Anticipated Duration (Months)

2416.4

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Hip fracture is a common serious injury in older adults that reduces mobility, independence, and quality of life, and can lead to premature death. Around 1.6 million cases occur globally per year, and continual increases in the number of older adults worldwide suggests that cases could reach 4.5 million by 2050. Diet can affect bone health and risk of hip fracture, with varying risks in adults on specific diets. There is some evidence that vegetarians may have poorer bone health and higher risks of fractures than meat-eaters, but prospective evidence for hip fractures is limited, and the influence of factors including diet quality and body mass index (BMI) are unclear.

The main aim of this research is to investigate risk of hip fracture in occasional meat-eaters, pescatarians, and vegetarians compared to regular meat-eaters. A secondary aim is to determine if risk of hip fracture in these diet groups depends on age, sex, diet quality, body mass index, and diet-gene interactions. Thirdly, we will explore the role of potential factors underpinning any risk differences, such as BMI, bone mineral density, and intake of nutrients that are mostly found in animal-sourced foods. The purpose of this study is to better understand hip fracture risk in vegetarian UK adults. The proposed project will use existing diet and lifestyle data from the UK Biobank resource, and hospital records of hip fractures.

Condition or Disease	Intervention/Treatment	Phase
Hip Fractures	Other: Dietary pattern observed

Detailed Description

Background:

Hip fracture is an increasingly prevalent health problem in the UK and worldwide that increases morbidity and mortality. Previous epidemiological evidence suggests that compared to meat-eaters, people following plant-based diets have lower bone mineral density (BMD) and a higher risk of fractures. Emerging evidence suggests a higher risk of hip fracture in vegetarian women, but prospective evidence of hip fracture risk in these diet groups is scarce and limited, particularly in men. Risk differences between diet groups are plausible in men and women, for example due to bone or muscle-related nutrient deficiencies or low BMI in vegetarians, but underlying mechanisms explaining potential risk differences require further investigation.

This study aims to investigate risk of hip fracture in occasional meat-eaters, pescatarians, and vegetarians compared to regular meat-eaters in the UK Biobank cohort. A secondary aim is to determine the role of potential modifying factors on associations between each diet group and hip fracture risk, including diet quality (determined by adherence to the Alternative Healthy Eating Index, AHEI), age, sex, and BMI, as well as investigating interactions between diet groups and genotypes on BMD and hip fracture risk. Thirdly, we aim to determine the role of potential mediating factors on any observed associations, including BMI, BMD, and intake of dietary nutrients abundant in animal products.

Research plan and methods:

The investigators will utilise dietary and lifestyle data from the UK Biobank cohort, which recruited over 500,000 adults between 2006-2010, and linked hospital records of UK Biobank participants to identify hip fracture cases.

A Cox regression model will be applied to investigate risk of hip fracture in each diet group compared to regular meat-eaters, and will be adjusted for relevant confounders. The roles of age, sex, AHEI score, BMI, and diet-gene interactions as potential effect modifiers will be explored by adding each variable to Cox regression models as interaction terms. Causal mediation analysis will be used to determine the role of potential mediators.

Study Design

Study Type:

Observational

Actual Enrollment :

500000 participants

Observational Model:

Cohort

Time Perspective:

Prospective

Official Title:

Risk of Hip Fracture in Meat-eaters, Pescatarians, and Vegetarians in the UK Biobank

Actual Study Start Date :

Jan 1, 2006

Actual Primary Completion Date :

Sep 30, 2021

Anticipated Study Completion Date :

Mar 31, 2023

Arms and Interventions

Arm	Intervention/Treatment
UK Biobank UK Biobank. There are no interventions in this observational cohort study.	Other: Dietary pattern observed Dietary pattern: regular meat-eater, occasional meat-eater, pescatarian, and vegetarian. There are no interventions in this observational cohort.

Arm

Intervention/Treatment

UK Biobank

UK Biobank. There are no interventions in this observational cohort study.

Other: Dietary pattern observed

Dietary pattern: regular meat-eater, occasional meat-eater, pescatarian, and vegetarian. There are no interventions in this observational cohort.

Outcome Measures

Primary Outcome Measures

Hip fracture incidence (first) [Age when the completed questionnaire was returned (2006-2010) until age at event, death, or end of study period (2021).]
First incidence of hip fracture, identified from all relevant ICD diagnosis codes and treatment codes identified through linked HES data.

Eligibility Criteria

Criteria

Ages Eligible for Study:

40 Years to 70 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

Male or female
Ages 40 to 70 years at time of recruitment
Able to provide informed consent

Exclusion Criteria:

Unable to link dietary and lifestyle data with hospital episode statistics
Had a hip fracture or osteoporosis before or no the date of recruitment
Withdrew consent during the study period
Genetic sex differs to reported sex
Outlier diet or anthropometric data (energy intake <500 or >5000 kcal/day or body mass index <10 or >60 kg/m2