Median HbA1c by Age and Sex: Temporal Cohort Findings (2012–2024)

Findings from three cross-sectional cohorts (2012, 2017, 2024) in Catanzaro, Southern Italy, were reported as showing broadly stable population-level median HbA1c over a 12-year span, alongside age-related heterogeneity and no consistently different pattern by sex. The authors described each dataset as an independent snapshot rather than follow-up of the same individuals, drawn from consecutive adults undergoing HbA1c testing within defined recruitment windows. Cohort sizes were reported as 1249 participants in 2012 and 1125 participants in both 2017 and 2024. The results are presented in the article as overall medians, a threshold-based distribution summary, and age- and sex-stratified comparisons.

The results table reports median HbA1c for each year by sex, including interquartile ranges and within-cohort sex comparisons. In 2012, women had a median of 7.35% (IQR 6.80–8.30) and men 7.30% (IQR 6.80–8.20), with the authors reporting a non-significant comparison. For 2017, the medians were reported as 7.30% in women and 7.40% in men. In 2024, both women and men were reported to have a median HbA1c of 7.40%, and the authors again reported no significant difference by sex. Across the three time points, the overall cohort summaries presented between-sex differences as small.

The authors also reported the proportion of participants with HbA1c ≥7.0% in each cohort year: 62.4% in 2012, 70.4% in 2017, and 71.8% in 2024. Alongside the narrow band of overall medians, the reported proportion with HbA1c ≥7.0% was higher in 2017 and 2024 than in 2012. In the article’s presentation, medians and HbA1c ≥7.0% proportions serve as complementary summaries of cohort glycemia rather than interchangeable metrics.

In age-stratified analyses, the authors described stability in older adults (≥70 years), with median values in both sexes clustering roughly in the 7.2%–7.6% range across the three cohorts, as shown in age-stratified HbA1c materials. Within this stratified presentation, they characterized sex differences as generally small, inconsistent, and dependent on age rather than uniform across the lifespan. They highlighted one statistically significant between-sex comparison in the ≥80-year stratum in 2017, with men reported to have slightly higher median HbA1c than women, while noting no significant sex differences in 2012 or 2024. Overall, the article framed sex-related findings as a narrow, age-specific signal amid otherwise modest differences.

More volatility was reported in younger adults, with the youngest strata (18–29 and 30–39 years) showing the highest medians in 2017 and then improvement by 2024 in both sexes. For the 18–29-year group, the article provided examples of this 2017-to-2024 shift: women were reported to decrease from 8.90% to 7.50%, and men from 8.10% to 7.20%. The authors presented these changes as part of broader age-dependent temporal heterogeneity across the three snapshots, with the largest temporal changes emphasized in the youngest strata rather than among older adults.

The authors addressed comparability across time by noting that HbA1c measurement used the ADAMS A1c HA-8160 analyzer in 2012 and the Premier Hb9210 in 2017 and 2024, with both methods described as NGSP-certified and IFCC-traceable. They further reported acceptable coefficients of variation and cited prior demonstrations of high correlation between the respective methods as part of their rationale for comparing cohorts across years. Among limitations explicitly listed, the article emphasized the cross-sectional independent-cohort design and missing clinical covariates—such as diabetes duration, BMI, and treatments—which the authors stated constrain inference about drivers of the observed patterns. These method and data-availability considerations were presented as key context for what the between-cohort comparisons can and cannot explain.

Key Takeaways:

• Across 2012, 2017, and 2024, overall cohort medians were reported to remain within a narrow band, with no consistently different population-level pattern by sex.
• Using a fixed HbA1c cutoff (≥7.0%) provided a distributional complement to the median-based summaries across cohorts.
• Age-stratified results placed the largest 2017→2024 improvements in younger adults, while older adults were reported as stable, with only an isolated age-specific sex difference noted in 2017.