Effect of vitamin D supplementation on total and allergen-specific IgE in children with asthma and low vitamin D levels.

BACKGROUND: Observational studies have yielded inconsistent findings for the relation between vitamin D level and total IgE or allergic sensitization. OBJECTIVE: To determine whether vitamin D supplementation reduces levels of total IgE and IgE to each of 2 common indoor allergens in children with asthma and low vitamin D levels. METHODS: Total IgE, IgE to Dermatophagoides pteronyssinus, and IgE to Blattella germanica were measured at the randomization and exit visits for 174 participants in the Vitamin D Kids Asthma Study, a multicenter, double-blind, randomized placebo-controlled trial of vitamin D3 supplementation (4000 IU/d) to prevent severe exacerbations in children with persistent asthma and vitamin D levels less than 30 ng/mL. Multivariable linear regression was used for the analysis of the effect of vitamin D supplementation on change in each IgE measure. RESULTS: Participants were followed for an average of 316 days. At the exit visit, more subjects in the vitamin D arm achieved a vitamin D level equal to or more than 30 ng/mL compared with those in the placebo arm (87% vs 30%; P < .001). In a multivariable analysis, vitamin D3 supplementation had no significant effect on change in total IgE, IgE to Dermatophagoides pteronyssinus, or IgE to Blattella germanica between the exit and randomization visits (eg, for log10 total IgE, ß = 0.007; 95% CI, -0.061 to 0.074; P = .85). CONCLUSIONS: Vitamin D supplementation, compared with placebo, has no significant effect on serum levels of total IgE, IgE to dust mite, or IgE to cockroach in children with asthma and low vitamin D levels.

Adjunctive Bright Light Therapy for Bipolar Depression: A Randomized Double-Blind Placebo-Controlled Trial.

OBJECTIVE: Patients with bipolar disorder have recurrent major depression, residual mood symptoms, and limited treatment options. Building on promising pilot data, the authors conducted a 6-week randomized double-blind placebo-controlled trial to investigate the efficacy of adjunctive bright light therapy at midday for bipolar depression. The aims were to determine remission rate, depression symptom level, and rate of mood polarity switch, as well as to explore sleep quality. METHOD: The study enrolled depressed adults with bipolar I or II disorder who were receiving stable dosages of antimanic medication (excluding patients with hypomania or mania, mixed symptoms, or rapid cycling). Patients were randomly assigned to treatment with either 7,000-lux bright white light or 50-lux dim red placebo light (N=23 for each group). Symptoms were assessed weekly with the Structured Interview Guide for the Hamilton Depression Scale With Atypical Depression Supplement (SIGH-ADS), the Mania Rating Scale, and the Pittsburgh Sleep Quality Index. Remission was defined as having a SIGH-ADS score of 8 or less. RESULTS: At baseline, both groups had moderate depression and no hypomanic or manic symptoms. Compared with the placebo light group, the group treated with bright white light experienced a significantly higher remission rate (68.2% compared with 22.2%; adjusted odds ratio=12.6) at weeks 4-6 and significantly lower depression scores (9.2 [SD=6.6] compared with 14.9 [SD=9.2]; adjusted ß=-5.91) at the endpoint visit. No mood polarity switches were observed. Sleep quality improved in both groups and did not differ significantly between them. CONCLUSIONS: The data from this study provide robust evidence that supports the efficacy of midday bright light therapy for bipolar depression.

Effects of aldosterone on insulin sensitivity and secretion.

Dr. Conn originally reported an increased risk of diabetes in patients with hyperaldosteronism in the 1950s, although the mechanism remains unclear. Aldosterone-induced hypokalemia was initially described to impair glucose tolerance by impairing insulin secretion. Correction of hypokalemia by potassium supplementation only partially restored insulin secretion and glucose tolerance, however. Aldosterone also impairs glucose-stimulated insulin secretion in isolated pancreatic islets via reactive oxygen species in a mineralocorticoid receptor-independent manner. Aldosterone-induced mineralocorticoid receptor activation also impairs insulin sensitivity in adipocytes and skeletal muscle. Aldosterone may produce insulin resistance secondarily by altering potassium, increasing inflammatory cytokines, and reducing beneficial adipokines such as adiponectin. Renin-angiotensin system antagonists reduce circulating aldosterone concentrations and also the risk of type 2 diabetes in clinical trials. These data suggest that primary and secondary hyperaldosteronism may contribute to worsening glucose tolerance by impairing insulin sensitivity or insulin secretion in humans. Future studies should define the effects of MR antagonists and aldosterone on insulin secretion and sensitivity in humans.

Human interventions to characterize novel relationships between the renin-angiotensin-aldosterone system and parathyroid hormone.

Observational studies in primary hyperaldosteronism suggest a positive relationship between aldosterone and parathyroid hormone (PTH); however, interventions to better characterize the physiological relationship between the renin-angiotensin-aldosterone system (RAAS) and PTH are needed. We evaluated the effect of individual RAAS components on PTH using 4 interventions in humans without primary hyperaldosteronism. PTH was measured before and after study (1) low-dose angiotensin II (Ang II) infusion (1 ng/kg per minute) and captopril administration (25 mg×1); study (2) high-dose Ang II infusion (3 ng/kg per minute); study (3) blinded crossover randomization to aldosterone infusion (0.7 µg/kg per hour) and vehicle; and study (4) blinded randomization to spironolactone (50 mg/daily) or placebo for 6 weeks. Infusion of Ang II at 1 ng/kg per minute acutely increased aldosterone (+148%) and PTH (+10.3%), whereas Ang II at 3 ng/kg per minute induced larger incremental changes in aldosterone (+241%) and PTH (+36%; P<0.01). Captopril acutely decreased aldosterone (-12%) and PTH (-9.7%; P<0.01). In contrast, aldosterone infusion robustly raised serum aldosterone (+892%) without modifying PTH. However, spironolactone therapy during 6 weeks modestly lowered PTH when compared with placebo (P<0.05). In vitro studies revealed the presence of Ang II type I and mineralocorticoid receptor mRNA and protein expression in normal and adenomatous human parathyroid tissues. We observed novel pleiotropic relationships between RAAS components and the regulation of PTH in individuals without primary hyperaldosteronism: the acute modulation of PTH by the RAAS seems to be mediated by Ang II, whereas the long-term influence of the RAAS on PTH may involve aldosterone. Future studies to evaluate the impact of RAAS inhibitors in treating PTH-mediated disorders are warranted.

Prevalence and clinical correlates of irritability in major depressive disorder: a preliminary report from the Sequenced Treatment Alternatives to Relieve Depression study.

BACKGROUND: Irritability is a common feature of major depressive disorder (MDD), though it is not included in the DSM-IV diagnostic criteria for adult MDD and is not assessed in most standard depression rating scales. Irritability with or without depression has been associated with risk for suicide, violence, and cardiovascular disease. METHOD: The prevalence of significant levels of irritability was examined among the first 1456 outpatients with nonpsychotic MDD entering the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study. Sociodemographic and clinical features were compared for participants who did and did not report irritability at least 50% of the time during the week preceding study entry. RESULTS: Of 1456 evaluable subjects, 582 (40%) reported irritability more than half the time. These individuals were more likely than nonirritable subjects to be female, to be younger, to be unemployed, and to report a history of at least 1 suicide attempt. Functional status and quality of life were also poorer in this group. Irritability was correlated with overall depressive severity, which accounted for nearly all of the clinical differences noted, with the exception of vascular disease, for which the association persisted after controlling for age, sex, and depressive severity. CONCLUSION: Irritability is prevalent among depressed outpatients and associated with a greater likelihood of suicide attempts, poorer functional status, and greater prevalence of vascular disease. It is correlated with overall depression severity and thus may not represent a distinct depressive subtype per se. The impact of irritability on course and treatment outcome merits further study.

Methods of testing feasibility for sequenced treatment alternatives to relieve depression (STAR*D).

In large multi-site trials, a feasibility or pilot study can be crucial to test the functionality of all aspects of conducting the study prior to the initiation of the formal study. A feasibility trial was conducted for the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) Project, a multi-site, prospective, sequentially randomized, clinical trial of outpatients with nonpsychotic major depressive disorder. From 14 December 2000 to 8 June 2001, 42 patients were screened for enrollment into the STAR*D Feasibility Trial. Twenty-four patients who were eligible and consented to participate were treated with citalopram for up to 12 weeks. During the course of this trial, issues were raised that resulted in modifications to the study procedures. Modifications made as a result of this trial affected four domains: (1) communication, (2) patient and provider burden, (3) data collection forms, and (4) recruitment and retention of subjects. This paper describes what was learned during the STAR*D Feasibility Trial so researchers planning to conduct similar trials can learn the practical issues related to conducting such a research project. While the information gathered was useful, it did delay the initiation of the formal trial. We view this cost as an investment in the development of overall study procedures that should lead to a stronger study.