When HDL was included, resulting in a smaller sample size, these associations remained significant.
Another limitation is the primarily white ethnicity of the Framingham study sample; hence, these associations need to be examined among community-dwelling individuals of other ethnicities.
Infections with C. parvum, I. belli, and G. intestinalis were associated with increasing water content of the stool samples, and these associations were all stronger after Mantel-Haenszel stratification for HIV status (data not shown).
But because of the small number of samples used, these associations are rather weak or even debatable [9], [11], [14].
We also utilised data from The Cancer Genome Atlas (TCGA) as a large, independent sample to evaluate these associations.
In the population-based sample, the associations were similar to that in the overall twin population.
However, in the setting of rare variation, accumulating sufficient samples to assess these associations can be difficult.
When we combined all five samples, none of these associations were significant, even though some of the SNPs showed similar direction of effects in some of the replication samples.
In each of these samples, the association between each predictor and the outcome was computed, and the predictors with a significant association were selected.
There was overlap between the NBS samples analysed both in this study and that of Codd et al. 13 However, even excluding these samples, the association between rs10936599 and telomere length remained (OR 0.673, 95% CI 0.511 to 0.886, p=5×10−3).
