Body mass index and infection risks in people with and without type 2 diabetes: A cohort study using electronic health records
Authors' conclusion
Infection risks are consistently higher for people with T2D but the association with increasing levels of BMI appears similar both in patients with and without diabetes. Additionally, being underweight is also associated with increased risk of infections requiring hospitalisation.
Study context
- Population
- People aged 18–90 alive on 1/1/2015 with body mass index (BMI) measured during 2011–14, CPRD; infections 2015–19 from primary care and linked hospitalisation recordsmatched cohort
- Participants
- 516,935 vs 751,909
- Exposure
- 12 BMI categories vs reference BMI >24-≤26 kg/m², in T2D and non-diabetes
- T2Dn = 516,935
- Non-diabetesn = 751,909
- Outcome
- Infection IRR across 12 BMI categories (≤19 to >48 kg/m²) vs BMI >24-≤26 kg/m², adjusted for age, sex, ethnicity, deprivation, smoking and co-morbidity
- Follow-up
- 2015-19
Methodological detailsmatched on age, sex and ethnicity, Clinical Practice Research Datalink, Poisson regression
- Matched on age, sex and ethnicity
- Clinical Practice Research Datalink
- Poisson regression
Main finding
As reported in the abstract
Hospitalisation-related infections, BMI >48 vs BMI >24-≤26
| Group | IRR | 95%CI |
|---|---|---|
| T2D | 2.35 | 2.26-2.44 |
| Non-diabetes | 2.52 | 2.30-2.75 |
IRR
T2D2.35
Non-diabetes2.52
95%CI
T2D2.26-2.44
Non-diabetes2.30-2.75
Observational data: associations, not effects.
Further findings
Infection type and setting
- Hospitalisation-related infections: U-shaped association with BMI not explained by age, smoking or co-morbidity
- Primary care infections: predominately associated with higher BMI levels only
- Cellulitis: strongest trends with high BMI levels
- Lower respiratory tract infection and sepsis: related to both high and low BMI levels
Original publication
Body mass index and infection risks in people with and without type 2 diabetes: A cohort study using electronic health records. Int J Obes (Lond). Published 18 July 2025. doi:10.
Composed by AI from the published abstract and checked against it. How Briefs are made →