Conduit vessel stiffness in British south Asians of Indian descent relates to 25-hydroxyvitamin D status.
BACKGROUND
South Asians migrating to Northern latitudes are more susceptible to premature cardiovascular disease (CVD) than expected for given levels of blood pressure. Vitamin D deficiency is common in this group and may play an important role mediating vascular wall senescence in response to central pressure effects.


METHODS
A cross-sectional association study. South Asian and White European participants were randomly recruited from a population-based diabetes-screening programme. Carotid-femoral pulse wave velocity (cfPWV), biochemistry (25-hydroxyvitamin D, fasting glucose), anthropometrics, resting blood pressure and a physical activity measure (International Physical Activity Questionnaire) were measured under controlled conditions.


METHODS
One hundred and thirty-two and 125 age-matched South Asians and White Europeans not taking vitamin D supplementation with a risk factor for diabetes but no overt CVD.


RESULTS
Age (mean south Asian: 55.7 vs. White European: 56.0 years), mean arterial pressure (MAP) and calculated CVD risk were similar in both groups. Unadjusted (cf)PWV (m/s) was higher (9.32 vs. 8.68 P = 0.001) and 25-hydroxyvitamin D (nmol/l) lower in (21.29 vs. 52.5 P < 0.001) south Asians. 25-Hydroxyvitamin D independently associated with cfPWV in multivariate modelling adjusted for age, MAP, sex, glucose, heart rate, vasoactive medication and south Asian ethnicity (R = 0.73, P = 0.004). 25-Hydroxyvitamin D but not physical activity was negatively correlated with cfPWV independent of south Asian ethnicity.


CONCLUSIONS
Aortic stiffness is increased in British Indo-Asians without vascular disease despite conventional risk profiles, which are comparable to age-matched white Europeans. This effect may be mediated by a greater pressure-dependent increase in stiffness in individuals with vitamin D insufficiency.
Department of Cardiovascular Sciences, Leicester Royal Infirmary University of Leicester, Leicester, Bedfordshire, UK. david.webb@uhl-tr.nhs.uk
David R
DR
Webb
Kamlesh
K
Khunti
Peter
P
Lacy
Laura J
LJ
Gray
Samiul
S
Mostafa
Duncan
D
Talbot
Bryan
B
Williams
Melanie J
MJ
Davies
D000328:Adult; D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000502:physiology; D002339:Carotid Arteries / Q000503:physiopathology; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004548:Elasticity; D005260:Female; D005263:Femoral Artery / Q000503:physiopathology; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000208:ethnology* / Q000503:physiopathology; D007194:India / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D011795:Surveys and Questionnaires; D006113:United Kingdom / Q000453:epidemiology; D014655:Vascular Resistance / Q000502:physiology*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000208:ethnology* / Q000503:physiopathology
D014807:Vitamin D; C104450:25-hydroxyvitamin D