Body mass index and all cause mortality in HUNT and UK Biobank studies: linear and non-linear mendelian randomisation analyses.
BMJ
; 364: l1042, 2019 03 26.
Article
en En
| MEDLINE
| ID: mdl-30957776
ABSTRACT
OBJECTIVE:
To investigate the shape of the causal relation between body mass index (BMI) and mortality.DESIGN:
Linear and non-linear mendelian randomisation analyses.SETTING:
Nord-Trøndelag Health (HUNT) Study (Norway) and UK Biobank (United Kingdom).PARTICIPANTS:
Middle to early late aged participants of European descent 56 150 from the HUNT Study and 366 385 from UK Biobank. MAIN OUTCOMEMEASURES:
All cause and cause specific (cardiovascular, cancer, and non-cardiovascular non-cancer) mortality.RESULTS:
12 015 and 10 344 participants died during a median of 18.5 and 7.0 years of follow-up in the HUNT Study and UK Biobank, respectively. Linear mendelian randomisation analyses indicated an overall positive association between genetically predicted BMI and the risk of all cause mortality. An increase of 1 unit in genetically predicted BMI led to a 5% (95% confidence interval 1% to 8%) higher risk of mortality in overweight participants (BMI 25.0-29.9) and a 9% (4% to 14%) higher risk of mortality in obese participants (BMI ≥30.0) but a 34% (16% to 48%) lower risk in underweight (BMI <18.5) and a 14% (-1% to 27%) lower risk in low normal weight participants (BMI 18.5-19.9). Non-linear mendelian randomisation indicated a J shaped relation between genetically predicted BMI and the risk of all cause mortality, with the lowest risk at a BMI of around 22-25 for the overall sample. Subgroup analyses by smoking status, however, suggested an always-increasing relation of BMI with mortality in never smokers and a J shaped relation in ever smokers.CONCLUSIONS:
The previously observed J shaped relation between BMI and risk of all cause mortality appears to have a causal basis, but subgroup analyses by smoking status revealed that the BMI-mortality relation is likely comprised of at least two distinct curves, rather than one J shaped relation. An increased risk of mortality for being underweight was only evident in ever smokers.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Índice de Masa Corporal
/
Causas de Muerte
Tipo de estudio:
Clinical_trials
/
Etiology_studies
/
Prognostic_studies
/
Risk_factors_studies
Límite:
Adult
/
Aged
/
Female
/
Humans
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Male
/
Middle aged
País/Región como asunto:
Europa
Idioma:
En
Revista:
BMJ
Asunto de la revista:
MEDICINA
Año:
2019
Tipo del documento:
Article
País de afiliación:
Noruega