Stroke is related to lower serum thyrotropin levels in patients with diabetes mellitus.
BACKGROUND
Low serum thyrotropin has been related to the presence of stroke as well as to a higher incidence of cardiovascular disease in the general population. Furthermore, abnormalities in serum thyrotropin have been observed in diabetic patients even if unaffected by known thyroid illness. On this basis we investigated whether stroke is associated with altered thyrotropin concentrations in a hospitalised population categorised for the presence of diabetes.


METHODS
This study used a database concerning all patients consecutively admitted to hospital and discharged alive with a diagnosis of stroke or of transient ischemic attacks (TIA) confirmed by clinical and CT criteria during an 18-month period. The study group was composed of 698 (392 M/306 F) patients, aged 74+/-12(SD) years of whom 372 were affected with TIA and 326 with stroke.


RESULTS
The median thyrotropin level was significantly lower in diabetic patients (0.91 mU/l) than in the non-diabetic group (1.3 mU/l; P=0.0001). Patients with stroke, compared to those with TIA, were older, had higher blood pressure, higher prevalence of diabetes and lower serum thyrotropin (median value in TIA group: 1.30 mU/l (95% CI 0.25-4.63) vs. 1.04 (95% CI 0.18-3.76) in the stroke group, P=0.03), stroke being significantly associated with reduced median thyrotropin only in diabetic patients (n=239; 0.82 mU/l, vs. 1.09 mU/l in diabetic group; P<0.05, and 1.21 mU/l vs. 1.37 mU/l in the non-diabetic group; P=NS). Stroke severity, as assessed by NIHSS, was weakly inversely related to thyrotropin levels. Finally, after adjusting for main confounders, the odds ratio for stroke in the first thyrotropin quartile was significantly higher only in diabetic patients (OR: 3.56; 95% CI: 1.55-8.19; P<0.01 by trend test).


CONCLUSIONS
In conclusion, our findings suggest that stroke is significantly associated with low serum thyrotropin in patients with diabetes.
Seghieri
Giuseppe
G
Department of Internal Medicine, Spedali Riuniti, Via Monte Sabotino 96/A, 51100 Pistoia, Italy. gseghier@tin.it
Bardini
Gianluca
G
Fascetti
Stefano
S
Moruzzo
Daniela
D
Franconi
Flavia
F
D000368:Aged; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood; D003920:Diabetes Mellitus / Q000097:blood*; D003925:Diabetic Angiopathies / Q000097:blood*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D002546:Ischemic Attack, Transient / Q000097:blood / Q000453:epidemiology; D008297:Male; D012189:Retrospective Studies; D020521:Stroke / Q000097:blood / Q000453:epidemiology*; D013972:Thyrotropin / Q000097:blood* / Q000172:deficiency
D015415:Biomarkers; D013972:Thyrotropin