Tuberculosis in patients with systemic rheumatic or pulmonary diseases treated with glucocorticosteroids and the preventive role of isoniazid: a review of the available evidence.

Development of tuberculosis (TB) is a concern in patients who receive glucocorticosteroids for the treatment of chronic rheumatic or pulmonary diseases. However, the incidence of development of TB in such patients and the prophylactic role of isoniazid (INH) are unclear. We evaluated the available evidence from 20 relevant prospective and retrospective cohort and case-control studies identified in the PubMed and Cochrane databases. The frequency of development of TB in the populations studied varied from 0% to 13.8%. This figure was low in studies performed in countries with a low incidence of TB (0% in the USA and Greece, 0.6% in France and 1.35% in Spain). In contrast, the frequency of development of TB in the studied cohorts was high in studies performed in countries with a moderate to high incidence of TB (from 2.5% in South Korea to 13.8% in The Philippines). Isoniazid prophylaxis (INHP) was found to decrease the incidence of development of TB in two of four studies that examined this intervention. The available evidence suggests that patients who receive steroids for the treatment of chronic rheumatic or pulmonary diseases and who live in countries with a high incidence of TB have a high risk of development of TB in contrast to patients who live in countries with a low incidence of the infection. However, the role of INHP even for patients living in countries where TB is endemic is unclear because the effectiveness of INH in preventing TB development in such patients is not well established and there are cost-effectiveness and safety issues.

Mechanisms in endocrinology: primary HT and risk for breast cancer: a systematic review and meta-analysis.

OBJECTIVE: The association between hypothyroidism and breast cancer has been described from very early on. Breast and thyroid tissue are interconnected on a molecular level mainly through activation of thyroid hormone receptors expressed on cells of the mammary gland as well as on the plasma membrane of breast cancer cells. Despite the experimental evidence the true value of hypothyroidism as a risk factor for breast cancer remains controversial. METHODS: We searched the PubMed database through February 2011 to identify studies that evaluated the association between hypothyroidism and risk for breast cancer as well as the effect of thyroid hormone replacement therapy on breast cancer incidence. RESULTS: A meta-analysis performed in 12 studies showed that hypothyroidism was not associated with risk for breast cancer (pooled risk ratio (RR)=1.06, 95% confidence intervals (CIs) 0.82-1.35, P = 0.672). The effect of treatment was assessed in seven studies and no evidence for an association between thyroid hormone replacement and breast cancer was observed with an overall RR of 0.99 (95% CI 0.73-1.35, P = 0.965). CONCLUSIONS: Our meta-analysis showed that hypothyroidism is not associated with increased risk for breast cancer and thyroid hormone replacement therapy does not reduce breast cancer prevalence; however, the heterogeneity of the studies analyzed precludes firm conclusions.

Association between thyroid function tests at baseline and the outcome of patients with sepsis or septic shock: a systematic review.

INTRODUCTION: The severity of critical illness is associated with various patterns of thyroid hormone abnormalities. We sought to evaluate whether the outcome of patients with, specifically, sepsis or septic shock is associated with the thyroid function tests evaluated at diagnosis or admission in the intensive care unit (ICU). METHODS: We performed a systematic review of relevant studies by searching PubMed. RESULTS: We included nine studies that all had a prospective cohort design. Seven involved children or neonates, and two involved adults. Mortality was the outcome evaluated in eight studies, while the length of ICU stay was evaluated in the remaining study. In univariate analysis, six of the nine included studies showed that either, free or total, triiodothyronine or thyroxine was lower in the group of patients with sepsis or septic shock who had unfavorable outcome than in those who had favorable outcome. Two other studies showed higher TSH values in the group of patients with unfavorable outcome. No significant relevant findings were observed in the remaining study. Regarding the correlation of sepsis prognostic scoring systems with thyroid function tests, the three studies that provided specific relevant data showed variable findings. DISCUSSION: Most of the relevant studies identified favor the concept that decreased thyroid function at baseline might be associated with a worse outcome of patients with sepsis or septic shock. Although these findings are not consistent, the role of thyroid function in affecting or merely predicting the outcome of sepsis or septic shock merits further investigation.