Nutrition in early life: somatic growth and serum lipids

Serum uric acid and risk of cardiovascular mortality: a prospective long-term study of 83,683 Austrian men

BACKGROUND

The role of serum uric acid (SUA) as an independent risk factor for cardiovascular disease (CVD) remains controversial, and little is known about its prognostic importance for mortality from congestive heart failure (CHF) and stroke. Few large-scale epidemiologic studies with sufficient follow-up have addressed the association of SUA and CVD mortality in apparently healthy men across a wide age range.

METHODS

A cohort of 83 683 Austrian men (mean age, 41.6 years) was prospectively followed for a median of 13.6 years. We used Cox proportional hazards models adjusted for established risk factors to evaluate SUA as an independent predictor for CVD mortality.

RESULTS

The highest quintile of SUA concentration (>398.81 mumol/L) was significantly related to mortality from CHF (P = 0.03) and stroke (P <0.0001); adjusted hazard ratios (95% confidence interval) for the highest vs lowest quintiles of SUA were 1.51 (1.03-2.22) and 1.59 (1.23-2.04), respectively. SUA was not associated, however, with mortality from acute, subacute, or chronic forms of coronary heart disease (CHD) after adjustment for potential confounding factors (P = 0.12). Age was a significant effect modifier for the relation of SUA to fatal CHF (P = 0.05), with markedly stronger associations found in younger individuals.

CONCLUSIONS

Our study demonstrates for the first time in a large prospective male cohort that SUA is independently related to mortality from CHF and stroke. Although increased SUA is not necessarily a causal risk factor, our results suggest the clinical importance of monitoring and intervention based on the presence of an increased SUA concentration, especially because SUA is routinely measured.

Independent association of high serum uric acid concentration with angiographically defined coronary artery disease

Epidemiological studies have shown that a high serum uric acid concentration is a risk factor for coronary artery disease (CAD). However, the issue of whether it is an independent cardiovascular risk factor or simply a marker of co-existing conditions is a matter of controversy. In the present case-controlled study, we explored the association between serum uric acid and angiographically defined CAD in middle-aged subjects (356 CAD patients and 350 healthy individuals). Serum uric acid in CAD patients was significantly higher than that in healthy individuals (359 +/- 88.7 and 289 +/- 79.3 micromol/l, respectively, p < 0.01) and remained significantly higher after adjusting for confounding factors (F = 79.77, p < 0.01). The association between uric acid and CAD was not limited to the hyperuricemic range of values, but was also found in the high-normal range (p < 0.01). An unadjusted odds ratio (OR) of 5.0 was obtained in both genders (p < 0.01). Female patients with > 50% stenosis (clinically significant CAD), regardless of the number of diseased vessels, had higher uric acid concentrations than those with < 50% stenosis even after adjusting for confounders (F = 3.79, p = 0.01). In conclusion, we have demonstrated that high serum uric acid is independently associated with CAD and that uric acid determination could be useful as one of the markers of clinically significant CAD.

Lower birth weight predicts metabolic syndrome in young adults: the Atherosclerosis Risk in Young Adults (ARYA)-study

OBJECTIVE

To study the relationship between intrauterine growth and the metabolic syndrome, particularly fasting serum lipids in young adulthood.

METHODS

Seven hundred and forty-four young adults aged 26-31 years participated in the ARYA birth cohort. Birth characteristics were available from charts kept by the Municipal Health Service, Utrecht, The Netherlands. Adult medical history and lifestyle information were assessed by questionnaires. Adult anthropometry, blood pressure, fasting plasma glucose, total cholesterol, HDL-cholesterol, triglycerides were measured, and LDL-cholesterol was calculated.

RESULTS

Subjects in the lower tertiles of birth weight (1250-3209 and 3210-3649 g) had higher risks for metabolic syndrome than those in the highest birth weight tertile (3650-5500 g): odds ratio, 1.8; 95% confidence interval (CI) 1.0-3.5 and 1.4; 0.7-2.7, respectively; p for trend = 0.064, adjusted for gender, cardiovascular disease family history and current education. Birth weight was inversely related to systolic blood pressure (linear regression coefficient, -1.9 mmHg/kg birth weight; 95% CI -3.4 to -0.3) and to (log) triglycerides in mmol/L (-0.03/kg birth weight; 95% CI -0.06 to -0.01), adjusted for gender, current body mass index and current education. Birth weight showed inverse relations to diastolic blood pressure, serum glucose, total and LDL cholesterol and positive relations to waist circumference and HDL cholesterol levels, although not statistically significant. Birth length and ponderal index were not related to the metabolic syndrome or lipid profiles.

CONCLUSION

Lower birth weight indicates a higher risk for metabolic syndrome in young adults, particularly through higher serum triglycerides and higher systolic blood pressure.

Relationship between birthweight and blood lipid concentrations in later life: evidence from the existing literature

BACKGROUND

It has been suggested that there is a link between fetal growth and chronic diseases later in life. Several studies have shown a negative association between birthweight and cardiovascular diseases, as well as cardiovascular disease risk factors, such as blood pressure and type 2 diabetes. Far fewer studies have focused on the association between size at birth and blood lipid concentrations. We have conducted a qualitative assessment of the direction and consistency of the relationship between size at birth and blood lipid concentrations to see whether the suggested relationship between intrauterine growth and cardiovascular diseases is mediated by lipid metabolism.

METHODS

A literature search covering the period January 1966 to January 2003 was performed using Medline, Embase, and Web of Science. All papers written in English and reporting the relationship between size at birth and lipid levels in humans were assessed. Bibliographies were searched for further publications.

RESULTS

From an initial screen of 1198 references, 39 papers were included involving 28 578 individuals. There was no consistent relationship between size at birth and blood lipid levels; the one exception being triglyceride concentration, which showed statistically significant negative or U-shaped, but not positive, relationships with birthweight.

CONCLUSION

This review does not strongly support a link between birthweight and blood lipid levels in later life. However, the research in this area is limited and in order to make any definitive conclusions, longitudinal studies with sufficient power, data, and prospective follow-up are needed.

Is there a pathogenetic role for uric acid in hypertension and cardiovascular and renal disease?

Hyperuricemia is associated with hypertension, vascular disease, renal disease, and cardiovascular events. In this report, we review the epidemiologic evidence and potential mechanisms for this association. We also summarize experimental studies that demonstrate that uric acid is not inert but may have both beneficial functions (acting as an antioxidant) as well as detrimental actions (to stimulate vascular smooth muscle cell proliferation and induce endothelial dysfunction). A recently developed experimental model of mild hyperuricemia also provides the first provocative evidence that uric acid may have a pathogenic role in the development of hypertension, vascular disease, and renal disease. Thus, it is time to reevaluate the role of uric acid as a risk factor for cardiovascular disease and hypertension and to design human studies to address this controversy.

Tracking of serum total cholesterol during childhood: an 8-year follow-up population-based family study in eastern Finland

AIM

To investigate the tracking of serum total cholesterol (TC) during childhood.

METHODS

All children born during 1981-1982 in a rural community of eastern Finland were followed at 6 mo, 7 y and 15 y of age. The full follow-up period was completed by 138 out of 205 children, of whom 82 (33 girls) had TC measured at 7 y and 15 y of age (-7 y, -15 y). The main outcome measurement was TC (mmol/L).

RESULTS

TC-7 y was significantly associated with TC-15 y (r = 0.655; p-value < 0.001). This correlation did not change significantly after accounting for confounders. Children in the highest tertile of TC-7 y had a significantly higher risk of being in the highest tertile of TC-15 y compared with children in other tertiles of TC-7 y (relative risk = 6.4 (2.9-13.9)). TC-15 y was predicted positively by TC-7 y (linear regression beta = 0.63; p-value < 0.001) and parental high TC (TC > or = 5.0 mmol/L in at least one parent) (beta = 0.58; p-value = 0.030). Birthweight had no significant association with TC during childhood.

CONCLUSION

The study confirmed the tracking of TC during childhood. The identification of children at risk of developing high TC during adolescence should take into consideration the child's previous TC values during childhood and parental TC status.

Clinical aspects of obesity in childhood and adolescence

The level of fatness of a child at which morbidity acutely and/or later in life increases is determined on an acturial basis. Direct measurements of body fat content, e.g. hydrodensitometry, bioimpedance, or DEXA, are useful tools in scientific studies. However, body mass index (BMI) is easy to calculate and is generally accepted now to be used to define obesity in children and adolescents clinically. An increased risk of death from cardiovascular disease in adults has been found in subjects whose BMI had been greater than the 75th percentile as adolescents. Childhood obesity seems to substantially increase the risk of subsequent morbidity whether or not obesity persists into adulthood. The genetic basis of childhood obesity has been elucidated to some extent through the discovery of leptin, the ob gene product, and the increasing knowledge on the role of neuropeptides such as POMC, neuropeptide Y (NPY) and the melanocyte concentrating hormone receptors (for example, MC4R). Environmental/exogenous factors largely contribute to the development of a high degree of body fatness early in life. Twin studies suggest that approximately 50% of the tendency toward obesity is inherited. There are numerous disorders including a number of endocrine disorders (Cushing's syndrome, hypothyroidism, etc.) and genetic syndromes (Prader-Labhard-Willi syndrome, Bardet Biedl syndrome, etc.) that can present with obesity. A simple diagnostic algorithm allows for the differentiation between primary or secondary obesity. Among the most common sequelae of primary childhood obesity are hypertension, dyslipidemia, back pain and psychosocial problems. Therapeutic strategies include psychological and family therapy, lifestyle/behaviour modification and nutrition education. The role of regular exercise and exercise programmes is emphasized. Surgical procedures and drugs used in adult obesity are still not generally recommended in children and adolescents with obesity. As obesity is the most common chronic disorder in industrialized societies, its impact on individual lives as well as on health economics has to be recognized more widely. This review is aimed towards defining the clinical problem of childhood obesity on the basis of current knowledge and towards outlining future research areas in the field of energy homoesostasis and food intake in relation to child health. Finally, one should aim to increase public awareness of the ever increasing health burden and economic dimension of the childhood obesity epidemic that is present around the globe.

Inverse association between birth weight, birth length and serum total cholesterol in adulthood

OBJECTIVES

To investigate whether impaired fetal growth, measured by low birth weight and short birth length, is linked with raised levels of serum lipids and increased risk and mortality of coronary heart disease.

DESIGN

The association between birth length, birth weight, Ponderal Index and total serum cholesterol was examined in 545 Danish men and women aged 31 to 51 years who participated in the Ebeltoft Health Promotion Project in Denmark.

RESULTS

No associations were found in women. For men, a negative association was found between birth weight and serum total cholesterol, with a fall in mean serum total cholesterol from 6.03 mmol/l at birth weight below 3300 g to 5.64 mmol/l at birth weight above 4000. A similar association was found between birth length and serum cholesterol, with a mean value of 6.23 mmol/l at birth length below 51 cm and a mean value of 5.56 mmol/l at birth length above 54 cm. No associations were found for Ponderal Index. Between 3% and 8% of the variance in serum total cholesterol could be explained by the statistical models used in this study.

CONCLUSION

Our findings support the hypothesis of a negative association between birth weight, birth length and elevated serum cholesterol in adult life, but only in men.

Familial aggregation of serum total cholesterol: a population-based family study in eastern Finland

BACKGROUND

The Finnish population has a high risk of coronary heart disease, which is associated to a high population level of serum total cholesterol (CHOL) already evident at early ages. The study investigated the familial aggregation of CHOL in a sample of families with young offspring from eastern Finland.

METHODS

Fifteen-year-old offspring were examined during 1996-1997 and their biological parents were examined during 1993-1994. A total of 224 children were invited and 184 families participated, of which 123 were included in the analysis with complete data. The main outcome measure was the CHOL (millimoles per liter).

RESULTS

Significant positive familial correlations of CHOL were found for the pairs of mother/offspring (r = 0.35, P < 0.001, n = 111), father/offspring (r = 0.29, P = 0.007, n = 82), mother/daughter (r = 0.46, P = 0.001, n = 49), mother/son (r = 0.27, P = 0.036, n = 62), and father/daughter (r = 0.35, P = 0.035, n = 36). The adjustments for the offspring's gender and body mass index (BMI) and the parent's age, BMI, education, and family history of acute myocardial infarction did not alter these results. There was a higher proportion of the offspring in the highest quartile of CHOL when the mother had CHOL > or =5 mmol/L (OR = 3.26, 95% CI = 1.2-8.9, n = 111).

CONCLUSIONS

The study confirmed the familial aggregation of CHOL. The consistent CHOL association between the mother and the offspring may indicate the key role of the mother for the primary prevention of hypercholesterolemia.

Lower proportion of CD45R0+ cells and deficient interleukin-10 production by formula-fed infants, compared with human-fed, is corrected with supplementation of long-chain polyunsaturated fatty acids

BACKGROUND

The immune consequences of adding 20:4n-6 and 22:6n-3 fatty acids to preterm infant formula are not known.

METHODS

The effect of feeding preterm infants (14-42 days of age) human milk (Human Milk group), infant formula (Formula group), or formula with added long-chain polyunsaturated fatty acids 20:4n-6 and 22:6n-3 (Formula + LCP group) on isolated peripheral blood lymphocytes (by flow cytometry) and lipid composition (by gas-liquid chromatography) was determined. Lymphocytes were stimulated in vitro with phytohemagglutinin to measure soluble interleukin (sIL)-2R and IL-10 production (by enzyme-linked immunosorbent assay).

RESULTS

With age, the percentage of CD3+ CD4+ T cells and the percentage of CD20+ cells increased in the Human Milk and Formula + LCP groups (P < 0.05), but not in the unsupplemented Formula group. Compared with the Formula group, CD4+ cells from the Formula + LCP and Human Milk groups expressed more CD45R0 (antigen mature) and less CD45RA (antigen naive) at 42 days of age (P < 0.05). At 42 days, IL-10 production was lower (P < 0.05) in cells of the Formula group than in cells of the Human Milk group. Production of IL-10 by the cells of the Formula + LCP group was not different from that produced by the Human Milk group cells. An age-related decrease (P < 0.05) in sIL-2R production by Formula + LCP lymphocytes was observed, but sIL-2R production at 42 days in the Formula + LCP group did not differ significantly from that in the Human Milk group. Compared with Formula alone, adding LCP to formula resulted in a lower C18:2n-6 and higher C20:4n-6 content in lymphocyte phospholipids (P < 0.05).

CONCLUSIONS

Adding LCP to a preterm infant formula resulted in lymphocyte populations, phospholipid composition, cytokine production, and antigen maturity that are more consistent with that in human milk-fed infants. This may affect the ability of the infant to respond to immune challenges.