Parity and risk of stroke

Ethnic differences in carotid intima-media thickness between UK children of black African-Caribbean and white European origin

BACKGROUND AND PURPOSE

UK black African-Caribbean adults have higher risks of stroke than white Europeans and have been shown to have increased carotid intima-media thickness (cIMT). We examined whether corresponding ethnic differences in cIMT were apparent in childhood and, if so, whether these could be explained by ethnic differences in cardiovascular risk markers.

METHODS

We conducted a 2-stage survey of 939 children (208 white European, 240 black African-Caribbean, 258 South Asian, 63 other Asian, 170 other ethnicity), who had a cardiovascular risk assessment and measurements of cIMT at mean ages of 9.8 and 10.8 years, respectively.

RESULTS

Black African-Caribbean children had a higher cIMT than white Europeans (mean difference, 0.014 mm; 95% CI, 0.008-0.021 mm; P<0.0001). cIMT levels in South Asian and other Asian children were however similar to those of white Europeans. Among all children, cIMT was positively associated with age, systolic and diastolic blood pressure and inversely with combined skinfold thickness and serum triglyceride. Mean triglyceride was lower among black African-Caribbeans than white Europeans; blood pressure and skinfold thickness did not differ appreciably. However, adjustment for these risk factors had little effect on the cIMT difference between black African-Caribbeans and white Europeans.

CONCLUSIONS

UK black African-Caribbean children have higher cIMT levels in childhood; the difference is not explained by conventional cardiovascular risk markers. There may be important opportunities for early cardiovascular prevention, particularly in black African-Caribbean children.

Number of children and change in markers of metabolic health over 9-years in men and women. Data from the DESIR study

AIM

Parity is associated with an increased risk of coronary heart disease and type 2 diabetes, possibly mediated by long-term modification of metabolic health. Studying associations between the number of children with health and disease in men in addition to women allows for differentiation between the social and lifestyle influences of child-rearing, and the biological influences of childbearing. We sought to determine whether the number of children is associated with the incidence of raised fasting glucose (fasting plasma glucose≥6.1 mmol/L) and changes in glucose, insulin, insulin resistance and β-cell function over 9-years.

METHODS

Analysis of 1798 women and 1737 men from the DESIR study.

RESULTS

The number of children was associated with change in fasting glucose for women (P(trend)=0.02) and men (P(trend)=0.03), and increased incidence of raised fasting glucose by 30% (95% CI: 15, 47%) per child for men, but not women (3% [95% CI: -8, 15%]). There was a J-shaped association between number of children and change in insulin (P=0.01) and insulin resistance (P=0.005) for women, and a reduction in β-cell function in parous women (P=0.07). Men with children had increases in insulin (P=0.02), insulin resistance (P=0.02), and β-cell function (P=0.07).

CONCLUSIONS

The number of children a person has is associated with changes in metabolic health indices long after childbirth for both men and women. The distinct gender differences in deterioration of metabolic health indices emphasize that childbearing and child-rearing are likely to have differential influences on metabolic health.