Alteration of serum pituitary hormone levels in postmenopausal women with stroke

Hypothalamic-pituitary dysfunction in critically ill patients with traumatic and nontraumatic brain injury

BACKGROUND

A significant number of studies have shown that critically ill patients with brain injury (BI) frequently exhibit abnormal pituitary hormonal responses during the immediate postinjury period.

DISCUSSION

The elucidation of endocrine alterations depends on the criteria used, the diagnostic tests applied, and the timing of testing in relation to BI. The pattern of the detected hormonal abnormalities shows considerable variability. Altered endocrine responses are due mostly to hypothalamic changes rather than to pituitary dysfunction. Several studies have examined the correlation between hormonal alterations and BI severity, but the results are inconsistent. Furthermore, it remains currently unclear whether and how pituitary abnormalities adversely affect the clinical course of BI patients during the period of critical illness. On the basis of current knowledge, with the exception of clinically significant relative adrenal deficiency and diabetes insipidus, the other endocrine alterations do not seem to require any therapeutic intervention in severely ill BI patients. It is also uncertain whether hormonal abnormalities detected in the early post-BI period persist for the rest of these patients' lives.

CONCLUSIONS

In view of current evidence indicating a high incidence of pituitary dysfunction even years following BI it is recommended that repetition of endocrine evaluation should be performed during the rehabilitation phase in all patients.

Stroke is related to lower serum thyrotropin levels in patients with diabetes mellitus

INTRODUCTION

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.

PATIENTS AND 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.

Melatonin rhythms in stroke patients

Very little is known regarding melatonin's circadian rhythm in stroke patients. We compared urinary-sulfatoxymelatonin (6-SMT), its major metabolite, in 11 extensive cortical and seven deep or lacunar stroke patients on day 3 or 4 and day 10 post-stroke. Urinary 6-SMT and creatinine measured every 4 h for 24 h starting at 06:00 h significantly fluctuated during the day in both types of stroke and did not differ between day 3 or 4 and day 10 post-stroke. However, in extensive cortical lesions, a delay in the 6-SMT excretion was observed in the first post-stroke days compared to day 10. We conclude that circadian oscillator is preserved in extensive cortical as well as in deep and lacunar strokes. Extensive cortical stroke might delay the melatonin surge during the first post-stroke days.