For example, in a study of 44 adults, aged ≥ 60 years, an interquartile increase in PM2.5 of the five-day mean was associated with a 14% (95%CI −5.4 to 37%) increase in CRP for all individuals and an 81% (95%CI 21 to 172%) increase in CRP among those with diabetes, obesity and hypertension [38]. Here, CRP is linked to diabetes mellitus.