HbA1c – ChrX (BMJ Open Diabetes Res Care 2020)

We carried out sex-stratified association analysis on chromosome X variants (imputed to 1000 Genomes Phase 3) for HbA1c in eight Asian population-based cohorts (10,005 East Asians and 2,051 South Asians). East Asians studies include Multi-Ethnic Cohort (MEC), Singapore Prospective Study Program (SP2), Living Biobank, Singapore Malay Eye Study (SiMES), Singapore Chinese Eye Study (SCES), Singapore Chinese Health Study (SCHS-MI), and Beijing Eye Study (BES). South Asians study includes Singapore Indian Eye Study (SINDI).

Each chromosome X variant was tested for association with HbA1c in two regression models. In the first model to obtain P-values, we used inverse-normalised residuals after regressing out age, age2, and the first three principle components to test for association with each variant. The second model regressed untransformed HbA1c values with age, age2, the first three principle components and genetic dosage for interpretable effect size change. We then carried out fixed-effects sample-size weighted meta-analysis as implemented in METAL meta-analysis tool to combine association statistics across the East Asians studies. We reported variants with association statistics in at least two studies.

The files are summary statistics from East Asians meta-analysis. Each file contains the following information:

  1. CHR: chromosome
  2. POS: position (hg19)
  4. N: Total sample size
  5. EFF_ALLELE: Effect allele
  6. NONEFF_ALLELE: Other allele
  7. EFF_ALLELE_FREQ: Effect allele frequency
  8. BETA: Effect estimate from analysis of untransformed HbA1c value
  9. SEBETA: Standard error of effect estimate
  10. ZSCORE: Combined z-statistics for the variant from sample-size weighted meta-analysis
  11. P: P-value

HbA1c male
HbA1c female

In press

Please refer any queries to Dr Xueling Sim (ephsx@nus.edu.sg)