Dorothy Martinez

Brain Glucose Metabolism in Hypothyroidism: A Positron Emission Tomography Study before and after Thyroid Hormone Replacement Therapy

CONTEXT Hypothyroidism is frequently associated with subtle behavioral and psychiatric symptoms. The consequences of inadequate thyroid hormone availability to brain metabolism are poorly understood. OBJECTIVE This study assessed the relationships between neuropsychiatric symptoms and changes in relative regional cerebral glucose metabolism in hypothyroid patients undergoing thyroid hormone replacement therapy. DESIGN, SETTING, AND OUTCOME MEASURE: Relative regional cerebral glucose metabolism was compared in 13 previously untreated hypothyroid patients and 10 healthy control participants. Effects of thyroid hormone replacement therapy (levothyroxine, 3 months) were assessed using neuropsychiatric measures and positron emission tomography with [(18)F]fluorodeoxyglucose. RESULTS Before treatment, hypothyroid patients exhibited lower regional activity than control subjects in the bilateral amygdala, hippocampus, and perigenual anterior cingulate cortex (ACC), left subgenual ACC, and right posterior cingulate cortex. Severity of depressive symptoms covaried negatively with pretreatment activity in the bilateral middle frontal gyrus and right subgenual and dorsal ACC. Thyroid hormone replacement therapy abolished pretreatment group differences in regional activity, robustly increased activity in the ventral ACC, and significantly reduced both clinician-rated and self-rated behavioral and psychiatric symptoms. Increased activity within the ventral ACC was associated with reduced somatic complaints, whereas increased activity within the dorsal ACC was associated with reduced depressive symptoms. CONCLUSIONS Reduction of the behavioral complaints during thyroid hormone therapy is associated with a restoration of metabolic activity in brain areas that are integral to the regulation of affect and cognition. The findings suggest that thyroid hormone modulates regional glucose metabolism and psychiatric symptoms in the mature brain.

MEMORY IMPROVEMENT WITH TREATMENT OF HYPOTHYROIDISM

The consequences of inadequate thyroid hormone availability to the brain and treatment effects of levothyroxine on cognitive function are still poorly understood. This study prospectively assessed the effects of thyroid replacement therapy on cognitive function in patients suffering from biochemical evidenced, untreated hypothyroidism. Significant effects between the untreated hypothyroid group and control group were limited to verbal memory retrieval. When assessing the effects of 3-month treatment, results revealed that the treated hypothyroid group had significant increased verbal memory retrieval. Results suggest that specific memory retrieval deficits associated with hypothyroidism can resolve after replacement therapy with levothyroxine.

Economic Benefits of Intensive Insulin Therapy in Critically Ill Patients: The Targeted Insulin Therapy to Improve Hospital Outcomes (TRIUMPH) Project

OBJECTIVE—The purpose of this study was to analyze the economic outcomes of a clinical program implemented to achieve strict glycemic control with intensive insulin therapy in patients admitted to the intensive care unit (ICU). RESEARCH DESIGN AND METHODS—A difference-in-differences (quasi-experimental) study design was used to examine the associations of an intensive insulin therapy intervention with changes in hospital length of stay (ICU and total), costs (ICU and total), and mortality. Hospital administrative data were obtained for 6,719 adult patients admitted between 2003 and 2005 to one of five intervention or four comparison ICUs in a large academic medical center. Linear regression models with log transformations and appropriate retransformations were used to estimate length of stay (LOS) and costs; logistic regressions were used to estimate mortality. RESULTS—After adjustment for observable patient characteristics and secular time trends, the intervention was consistently associated with lower average glucose levels and a trend toward shorter LOS, lower costs, and lower mortality. However, associations with resource use and outcomes were statistically significant in only ICU LOS, with an average reduction of 1.19 days of ICU care per admission. Other associations, although large in magnitude and in the hypothesized directions, were not estimated with sufficient precision to rule out other net effects. The associations with ICU days and costs were larger in magnitude than total days and costs. CONCLUSIONS—A clinical team focused on hyperglycemia management for ICU patients can be a valuable investment with significant economic benefits for hospitals.

Economic Benefits of Intensive Insulin Therapy in Critically Ill Patients: The TRIUMPH Project

OBJECTIVE—The purpose of this study was to analyze the economic outcomes of a clinical program implemented to achieve strict glycemic control with intensive insulin therapy in patients admitted to the intensive care unit (ICU). RESEARCH DESIGN AND METHODS—A difference-in-differences (quasi-experimental) study design was used to examine the associations of an intensive insulin therapy intervention with changes in hospital length of stay (ICU and total), costs (ICU and total), and mortality. Hospital administrative data were obtained for 6,719 adult patients admitted between 2003 and 2005 to one of five intervention or four comparison ICUs in a large academic medical center. Linear regression models with log transformations and appropriate retransformations were used to estimate length of stay (LOS) and costs; logistic regressions were used to estimate mortality. RESULTS—After adjustment for observable patient characteristics and secular time trends, the intervention was consistently associated with lower average glucose levels and a trend toward shorter LOS, lower costs, and lower mortality. However, associations with resource use and outcomes were statistically significant in only ICU LOS, with an average reduction of 1.19 days of ICU care per admission. Other associations, although large in magnitude and in the hypothesized directions, were not estimated with sufficient precision to rule out other net effects. The associations with ICU days and costs were larger in magnitude than total days and costs. CONCLUSIONS—A clinical team focused on hyperglycemia management for ICU patients can be a valuable investment with significant economic benefits for hospitals.

Comparison of the relationship of age and beta cell function in three ethnic groups

Design  Prevalence of type 2 diabetes and glucose intolerance increase with age. It has been demonstrated that beta cell function declines at about 1% per year in glucose tolerant Caucasians. However, this relationship is not known to exist in other ethnic groups.

Combined Pharmacologic Therapy in Postmenopausal Osteoporosis

Antiresorptive agents for treating postmenopausal osteoporosis include selective estrogen receptor modulator (SERM), bisphosphonates and denoumab. Teriparatide is the only Food and Drug Administration-approved anabolic agent. Synergistic effects of combining teriparatide with an antiresorptive agent have been proposed and studied. This article reviews the trial designs and the outcomes of combination therapies. Results of the combination therapy for teriparatide and bisphosphonates were mixed; while small increases of bone density were observed in the combination therapy of teriparatide and estrogen/SERM and that of teriparatide and denosumab. Those clinical studies were limited by small sample sizes and lack of fracture outcomes.

Antibodies in autoimmune thyroiditis affect glucose metabolism of anterior cingulate.

BACKGROUND Hypothyroidism induced by an autoimmune process is associated with neuropsychiatric symptoms and metabolic abnormalities in the brain. The aim of this study was to examine the relationship between autoimmune thyroiditis and regional brain function in hypothyroid patients. METHODS Cerebral glucose metabolism, as an index of brain function, was assessed in regional whole-brain analyses using positron emission tomography (PET) and [18F]fluorodeoxyglucose in thirteen hypothyroid patients with autoimmune thyroiditis suffering from neuropsychiatric symptoms. The primary biological measures were radioactivity in pre-selected brain regions, relative to whole-brain radioactivity, as a surrogate index of glucose metabolism, and serum levels of thyroglobulin (TG) and thyroid peroxidase (TPO) antibodies as endocrine markers of autoimmune thyroiditis. RESULTS Serum levels of anti-TG antibodies in hypothyroid patients were significantly correlated with glucose metabolism in the perigenual anterior cingulate cortex, a brain region previously shown to regulate affect and emotional homeostasis. CONCLUSION Thyroid autoimmune processes may play an important role in the still poorly defined pathogenic correlates of disturbed function in brain regions critically involved in emotional processing in hypothyroid conditions.