The educational gradient in cardiovascular risk factors: impact of shared family factors in 228,346 Norwegian siblings

• Published in: BMC public health Vol. 17; no. 1; pp. 281 - 9
• Main Authors: Ariansen, Inger, Mortensen, Laust Hvas, Graff-Iversen, Sidsel, Stigum, Hein, Kjøllesdal, Marte Karoline Råberg, Næss, Øyvind
• Format: Journal Article
• Language: English
• Published: London BioMed Central 30.03.2017; BioMed Central Ltd; BMC
• Subjects: Adult; Adults; Age; Attenuation; Biostatistics; Blood pressure; Body mass index; Brothers and sisters; Cardiology: 771; Cardiovascular disease; Cardiovascular disease risk factors; Cardiovascular diseases; Cardiovascular Diseases - epidemiology; Cardiovascular Diseases - etiology; Cardiovascular Diseases - genetics; Children; Cholesterol; Clinical medical disciplines: 750; Confidence intervals; Education; Educational attainment; Educational Status; Environmental Health; Epidemiology; Family study; Female; Genetic Predisposition to Disease; Health aspects; Health behavior; health promotion and society; Health risk assessment; Health risks; Health Surveys; Heart diseases; Heart rate; Humans; Kardiologi: 771; Klinisk medisinske fag: 750; Male; Medical disciplines: 700; Medicine; Medicine & Public Health; Medisinske Fag: 700; Middle Aged; Norway - epidemiology; Polls & surveys; Population; Population studies; Position indicators; Public Health; Research Article; Risk analysis; Risk Factors; Siblings; Smoking; Socioeconomic factors; Socioeconomic position; Studies; Surveys; Vaccine; VDP; United Kingdom; ANE, Norway; Cardiovascular disease risk factors; Socioeconomic position; Education; Family study; Siblings
• ISSN: 1471-2458; 1471-2458
• DOI: 10.1186/s12889-017-4123-0

Background Various indicators of childhood socioeconomic position have been related to cardiovascular disease (CVD) risk in adulthood. We investigated the impact of shared family factors on the educational gradient in midlife CVD risk factors by assessing within sibling similarities in the gradient using a discordant sibling design. Methods Norwegian health survey data (1980–2003) was linked to educational and generational data. Participants with a full sibling in the health surveys (228,346 individuals in 98,046 sibships) were included. Associations between attained educational level (7–9 years, 10–11 years, 12 years, 13–16 years, or >16 years) and CVD risk factor levels in the study population was compared with the corresponding associations within siblings. Results Educational gradients in risk factors were attenuated when factors shared by siblings was taken into account: A one category lower educational level was associated with 0.7 (95% confidence interval 0.6 to 0.8) mm Hg higher systolic blood pressure (27% attenuation), 0.4 (0.4 to 0.5) mmHg higher diastolic blood pressure (30%), 1.0 (1.0 to 1.1) more beats per minute higher heart rate (21%), 0.07 (0.06 to 0.07) mmol/l higher serum total cholesterol (32%), 0.2 (0.2 to 0.2) higher smoking level (5 categories) (30%), 0.15 (0.13 to 0.17) kg/m 2 higher BMI (43%), and 0.2 (0.2 to 0.2) cm lower height (52%). Attenuation increased with shorter age-difference between siblings. Conclusion About one third of the educational gradients in modifiable CVD risk factors may be explained by factors that siblings share. This implies that childhood environment is important for the prevention of CVD.