Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

OBJECTIVE:Given the high risk of cardiovascular disease in South Asians and the importance of inflammation in coronary heart disease we tested the hypothesis that circulating C-reactive protein (CRP) and interleukin 6 (IL-6) would be higher in healthy British born infants of South Asian origin than in infants of European origin in the first 2 years of life. STUDY DESIGN AND SETTING:Infants of South Asian (n=74) and European (n=129) origin were followed prospectively from birth. Anthropometry and fasting CRP and IL-6 concentrations were measured at one or more of 3, 6, 12 and 24 months of age. RESULTS:South Asian infants had a significantly lower circulating CRP compared with European infants (beta=0.63, 95% CI 0.41-0.98 mg/l, P=0.040). There was no significant change in CRP from birth to 2 years in either ethnic group so that neither infant weight nor weight gain were associated with CRP during follow-up. IL-6 concentrations were low or undetectable during follow-up in all participants. CONCLUSION:In our cohort, South Asian origin infants had significantly lower markers of inflammation compared with European infants. Infant growth to age 2 years was not associated with CRP or IL-6. Inflammatory markers are not useful indices of CVD risk at this age, with such markers not being elevated as expected in South Asian infants. The timing of the rise of such markers to the levels found in adult South Asian populations needs longer prospective study.

IGF-I and its binding proteins (BP) may modulate cardiovascular risk, from young ages. We examined relationships of IGF system indices (IGF-I, -BP-1, BP-3, IGF-I/BP-3 ratio) to cardiac and vascular structure function across the whole vascular bed. 193 women in our Manchester Mothers’ Cardiovascular (CVS) study followed from an index pregnancy aged 32±5y had fasting blood samples, anthropometry, echocardiography, aortic pulse wave velocity and heat augmented laser doppler flowmetry (LDF). In a smaller subgroup (n = 29), subcutaneous small artery structure and function was assessed ex-vivo by wire myography. IGF-I and IGFBP-3 were assayed by Elisa, and IGFBP-1 by radio-immunoassay. On multiple regression analysis, adjusting for age, ethnicity, smoking history, BMI, systolic blood pressure, fasting glucose, total cholesterol and triglycerides, IGF-I, IGFBP1 and the IGF-I/BP-3 ratio were independently related to CVS parameters as follows: In relatively young women, higher concentrations of IGF-I, ‘free’ IGF-I (= IGF-I/BP-3 ratio) and of IGFBP-1 had marked influences on cardiac, large and small vessel structure and function.

Abstract Background The insulin-like growth factor (IGF) system is implicated in the pathogenesis of diabetes and cardiovascular disease. Objective We report the effects of total energy intake on the IGF system in two populations with markedly different dietary macronutrient intake and cardiovascular event rate. Design, subjects and setting Dietary macronutrient intake was measured in a specific Gujarati migrant community in Sandwell, UK (n = 205) compared with people still resident in the same villages of origin in India (n = 246). Fasting IGF-I, IGF-binding protein (IGFBP)-1 and IGFBP-3, insulin and glucose (0 and 2-hour) were measured. Results Total energy and total fat intake were higher in UK migrants, as were IGFBP-3 and IGF-I (mean (95% confidence interval): 145.9 (138.1–153.6) vs. 100.9 (94.6–107.3) ng ml-1; F = 76.6, P < 0.001). IGFBP-1 was lower in UK migrants (29.5 (25.9–33.0) vs. 56.5 (50.6–62.5) μg l-1; F = 48.4, P < 0.001). At both sites, IGF-I correlated positively with total energy (Spearman's ρ = 0.45, P < 0.001) and total fat (ρ = 0.44, P < 0.001) as did IGFBP-3 with total energy (ρ = 0.21, P < 0.05) and fat (ρ = 0.26, P < 0.001). Conversely, in Indian Gujaratis, IGFBP-1 fell with increasing total energy (ρ = -0.27, P < 0.001) and fat intake (ρ = -0.26, P < 0.01) but not in UK Gujaratis. Multiple linear regression modelling showed that increasing quartiles of fat intake were associated with higher IGF-I (β = 0.42, P = 0.007) independent of age, body mass index, plasma insulin, fatty acids and 2-hour glucose. Conclusion In these genetically similar groups, migration to the UK and adoption of a different diet is associated with marked changes in the IGF system, suggesting that environmental factors profoundly modulate serum concentrations and actions of IGFs.

We previously reported independent links between the IGF system and the development of impaired glucose tolerance and cardiovascular risk. This study tests the hypothesis that the lifestyle change which accompanies population migration, with attendant increases in cardiovascular risk, is reflected by changes in the IGF system.

There are two key methods in which fat intake may be manipulated; the ‘substitution model’ and the ‘reduction model’. However insufficient information is known about the mechanisms of dietary fat reduction in individuals who have successfully reduced their fat intake, to be clear as to which strategy offers the greatest chance of success. Our objective was to ascertain the most effective dietary intervention for improving cardiovascular risk profile. Eighty female volunteers (high fat consumers) were recruited. Each subject was randomly allocated into one of the following groups. Substitution of high-fat foods was made with reduced-fat products, by the reduction of high-fat foods, by a combination of substitution and reduction strategies, or no advice was given. Each intervention lasted 3 months. Anthropometric measures and fasting blood samples were taken at baseline and follow-up. The substitution intervention resulted in weight loss (mean −1.4 (95% CI −2.4, −0.2) kg) and reduced percentage body fat (mean −1.3 (95% CI −2.0, −0.5)%). There was no significant weight change with the other interventions. Fasting triacylglycerols (−0.2 (SEM 0.07) mM;P=0.04), cholesterol and C-reactive protein (CRP) levels (0.8 (SEM 0.2) mg/l;P=0.04) fell with the substitution intervention, but not with the other interventions. Insulin-like growth factor-1 increased with both substitution and reduction (P=0.02). There was no significant change in fasting insulin or glucose with any intervention. The substitution model of dietary intervention is effective even over a relatively short interval of time in reducing fasting total cholesterol, triacylglycerols and CRP. Although the group size for the present study was small and involved females only, it has significant implications for population intervention strategies.