AimsTo evaluate 99th percentile upper reference limits (URLs) and investigate ethnic differences for the Abbott Architect high-sensitivity cardiac troponin I (hs-cTnI) in a middle-aged to elderly cosmopolitan population.MethodsIn subjects without cardiovascular disease and after outlier exclusion, data on hs-cTnI from 149 white men, 150 white women, 150 South Asian (SA) men and 150 SA women in their sixth, seventh and eight decades were analysed. Each ethnicity–gender–decade subgroup consisted of 50 patients except white men in their sixth decade (n=49).ResultsThe overall, women and men hs-cTnI 99th percentile URLs were 22.1, 17.9 and 24.8 ng/L, respectively. Median (IQR) hs-cTnI was higher in men (2.7 (1.8–4.1) ng/L) than in women (1.9 (1.1–3.2) ng/L; p<0.001). White men (3.2 (2.2–4.4) ng/L) had higher hs-cTnI than SA men (2.5 (1.6–3.6) ng/L; p<0.001), white women (2.1 (1.3–3.3) ng/L; p<0.001) and SA women (1.6 (1.0–3.0) ng/L; p<0.001). Hs-cTnI in white women was similar to SA women (p=0.07) and SA men (p=0.07). Patients in the eighth decade had higher hs-cTnI (p<0.05) than those in sixth decade within each ethnicity–gender subgroup. Of significant associations, age had the greatest impact on hs-cTnI followed by gender and then ethnicity.ConclusionWe report white–SA differences in hs-cTnI in men and a similar trend in women. We confirm age and gender differences in hs-cTnI, irrespective of ethnicity. Further studies are required to determine whether ethnicity-specific age and gender 99th percentile URLs improve detection or exclusion of myocardial injury.

Herbal remedies adulterated with glucocorticoids can cause Cushing’s syndrome. We report a severe presentation of a ‘herbal remedy’ adulterated with glucocorticoids; causing a potentially fatal adrenal crisis precipitated by acute illness. Investigations were consistent with adrenal suppression and confirmed, after tablet analysis, to be due to a ‘herbal remedy’ containing synthetic betamethasone/dexamethasone. This case highlights the need for clinical vigilance and patient education about the potential risks associated with the use of unlicensed treatments and the role of tablet analysis in routine biochemistry.