Is birth weight related to later glucose and insulin metabolism?--A systematic review

AIM

To determine the relationship of birth weight to later glucose and insulin metabolism.

METHODS

Systematic review of the published literature. Data sources were Medline and Embase. Included studies were papers reporting the relationship of birth weight with a measure of glucose or insulin metabolism after 1 year of age, including the prevalence of Type 2 diabetes mellitus (DM). Three reviewers abstracted information from each paper according to specified criteria.

RESULTS

Forty-eight papers fulfilled the criteria for inclusion, mostly of adults in developed countries. Most studies reported an inverse relationship between birth weight and fasting plasma glucose concentrations (15 of 25 papers), fasting plasma insulin concentrations (20 of 26), plasma glucose concentrations 2 h after a glucose load (20 of 25), the prevalence of Type 2 DM (13 of 16), measures of insulin resistance (17 of 22), and measures of insulin secretion (16 of 24). The predominance of these inverse relationships and the demonstration in a minority of studies of other directions of the relationships could not generally be explained by differences between studies in the sex, age, or current size of the subjects. However, the relationship of birth weight with insulin secretion was inconsistent in studies of adults.

CONCLUSIONS

The published literature shows that, generally, people who were light at birth have an adverse profile of later glucose and insulin metabolism. This is related to higher insulin resistance, but the relationship to insulin secretion in adults is less clear.

Intake of micronutrient-rich foods in rural Indian mothers is associated with the size of their babies at birth: Pune Maternal Nutrition Study

One third of the Indian babies are of low birth weight (<2.5 kg), and this is attributed to maternal undernutrition. We therefore examined the relationship between maternal nutrition and birth size in a prospective study of 797 rural Indian women, focusing on macronutrient intakes, dietary quality and micronutrient status. Maternal intakes (24-h recall and food frequency questionnaire) and erythrocyte folate, serum ferritin and vitamin C concentrations were measured at 18 +/- 2 and 28 +/- 2 wk gestation. Mothers were short (151.9 +/- 5.1 cm) and underweight (41.7 +/- 5.1 kg) and had low energy and protein intakes at 18 wk (7.4 +/- 2.1 MJ and 45.4 +/- 14.1 g) and 28 wk (7.0 +/- 2.0 MJ and 43.5 +/- 13.5 g) of gestation. Mean birth weight and length of term babies were also low (2665 +/- 358 g and 47.8 +/- 2.0 cm, respectively). Energy and protein intakes were not associated with birth size, but higher fat intake at wk 18 was associated with neonatal length (P < 0.001), birth weight (P < 0.05) and triceps skinfold thickness (P < 0.05) when adjusted for sex, parity and gestation. However, birth size was strongly associated with the consumption of milk at wk 18 (P < 0.05) and of green leafy vegetables (P < 0.001) and fruits (P < 0.01) at wk 28 of gestation even after adjustment for potentially confounding variables. Erythrocyte folate at 28 wk gestation was positively associated with birth weight (P < 0.001). The lack of association between size at birth and maternal energy and protein intake but strong associations with folate status and with intakes of foods rich in micronutrients suggest that micronutrients may be important limiting factors for fetal growth in this undernourished community.

The stability between two HIV-1 RNA measurements one year apart and the relationship with HIV subtype in rural Uganda

We compared HIV-1 RNA levels using the nucleic acid sequenced based amplification (NASBA) test kit in 2 samples taken one year apart from participants infected with env subtype A or D in a population-based cohort in Uganda. Fifty participants were infected with subtype A and 70 with subtype D. HIV-1 RNA levels were significantly higher in subtype D unadjusted (P=0.001), and after adjusting for age, gender, and CD4 count (P<0.001). Eighty-six participants had HIV-1 RNA measurements in both years and 67 (78%) were within one log10 of their result a year before. There was no relationship between the difference in log viral load and proportion of CD4 change. Individuals infected with subtype D had a higher average increase in viral load and this was statistically significant if adjusted for baseline levels and CD4 count (P=0.015).

Predicting the community prevalence of schistosomiasis mansoni from the prevalence among 7- to 14-year-olds

The World Health Organization suggested that the prevalence of Schistosoma mansoni among 7- to 14-year-olds be used to guide treatment strategies in endemic areas. This study explores how well the prevalence in that age group predicted the overall prevalence in the community in data from stool examinations (Kato-Katz method) from 180,000 people in 3 municipalities in Brazil in 1984 and 1985. The median prevalence was higher in 1984, before community treatment was introduced. There was a strong relationship between the prevalence among 7- to 14-year-olds and the overall prevalence in the community. We present sensitivities and positive predictive values for the use of prevalence in the indicator group to select communities for mass treatment as recommended by WHO. For a range of assumptions sensitivity and positive predictive value were never both above 80 %. We suggest that the estimates of validity presented in this paper inform future evaluations of strategies for S. mansoni control.

Blood pressure, arterial compliance, and left ventricular mass: no relation to small size at birth in south Indian adults

OBJECTIVE

To determine whether reduced fetal growth leads to raised blood pressure, reduced arterial compliance, and increased left ventricular mass in an Indian population.

DESIGN

A retrospective cohort study of men and women (age range 40-61 years) whose weight, length, and head circumference at birth were recorded.

SETTING

The Holdsworth Memorial Hospital, Mysore, South India.

SUBJECTS

435 men and women born in the hospital between 1934 and 1953.

MAIN OUTCOME MEASURES

Systolic and diastolic blood pressures; compliance in four arterial segments derived from pulse wave velocity, measured by a non-invasive optical method; and left ventricular mass measured using M mode echocardiography.

RESULTS

Small size at birth was not associated with increased adult blood pressure or left ventricular mass, or with reduced arterial compliance. Systolic blood pressure and left ventricular mass were higher in subjects who were greater in length at birth, rising by 1.64 mm Hg (95% confidence interval (CI) -0.08 to +3.37 mm Hg) and 1.63 g/m(2) (95% CI 0.13 to 3.13 g/m(2)), respectively, per one inch (2.5 cm) increase in birth length, independently of adult size. Arterial compliance was reduced in people whose mothers were lighter and had smaller pelvic (external conjugate) diameters.

CONCLUSIONS

The higher prevalence of coronary heart disease in Indian men and women of lower birth weight, shown in an earlier study of the same cohort, cannot be explained by changes in blood pressure, arterial compliance, and left ventricular mass. The association of raised blood pressure and left ventricular mass with longer birth length suggests that the way in which the intrauterine environment influences coronary heart disease differs between Indian and Western populations.