Biomarkers of ageing in New Zealand VLBW young adults and controls.

BACKGROUND: There is individual variation in physiological ageing. Former very low birthweight (VLBW; birthweight < 1500 g) young adults may have less satisfactory measurements on some physiological parameters than term controls. We hypothesized that a summation score of physiological biomarkers that change with age would show VLBW adults to have a more advanced physiologic age than controls. METHODS: VLBW adults (229; 71% survivors of a national VLBW cohort) and term-born controls (100) were clinically assessed at 26-30 years. Ten measured physiological biomarkers were selected and measurements converted to z-scores using normative reference data. Between-group comparisons were tested for statistical significance for individual biomarker z-scores and a summation score. RESULTS: Nine of 10 biomarkers showed a mean z-score suggestive of older physiological age in the VLBW group versus controls. The observed mean difference in the summation score was highly significant (p < 0.001), representing a mean shift of 0.47 SD in the distribution of test scores for VLBW relative to controls. CONCLUSIONS: Utilizing a 10-biomarker score, VLBW young adults have a score indicative of poorer physiological functioning than term-born controls. Repeating these measures after an interval could provide insights into the comparative pace of ageing between VLBW and term-born adults. IMPACT: A summation score of 10 physiological biomarkers that are known to change with age shows that former very low birthweight adults have significantly poorer physiological functioning by the end of their third decade than term-born controls. This result adds to existing literature showing very preterm and very low birthweight young adults often have physiological and metabolic test results that are less satisfactory than those from term controls, despite mostly being in the normal range for age; for instance, higher systolic blood pressure. Although the pace of ageing in later years is yet to be established, the implications of this study are that preventative measures and lifestyle choices that impact on physiological ageing might have even greater importance for very preterm and very low birthweight graduates.

Is childhood oral health the 'canary in the coal mine' for poor adult general health? Findings from two New Zealand birth cohort studies.

OBJECTIVES: This study aimed to investigate whether childhood dental caries was associated with self-reported general health in midlife. METHODS: We used data on childhood oral health (caries experience) and adult self-reported general health from two New Zealand longitudinal birth cohorts, the Dunedin Multidisciplinary Health and Development Study (n = 922 and n = 931 at ages 5 and 45 years, respectively), and the Christchurch Health and Development Study (n = 1048 and n = 904 at ages 5 and 40 years, respectively). We used generalized estimating equations to examine associations between age-5 dental caries and self-rated general health and the number of self-reported physical health conditions at ages 45/40 (diagnosed by a doctor or health professional, n = 14 conditions among both cohorts). Covariates included known risk factors for poor health (SES, IQ, perinatal complications), and personality style, which is known to affect subjective health ratings. RESULTS: Incidence rate ratios for 'Excellent' self-rated health were lower among those who had high experience of dental caries as children than those who had not in both, the Dunedin (IRR, 0.76; 95% CI, 0.50, 1.14) and Christchurch studies (IRR, 0.69; 95% CI, 0.47, 1.00). Childhood dental caries was not associated with the number of self-reported physical health conditions in midlife, in either cohort. Dunedin Study members who at age 5 were not caries-free or whose parents rated their own or their child's oral health as poor were less likely to report 'Excellent' self-rated general health at age 45 than those who were caries-free and whose parents did not give a 'poor' rating (IRR, 0.69; 95% CI, 0.49, 0.97). CONCLUSIONS: Five-year-olds with greater caries experience were more likely to have poorer self-rated general health by midlife. Beyond this longitudinal association, future research should examine whether childhood dental caries is associated with objective/biological markers of physical health and whether it may have utility as an early indicator for poor general health in adulthood.