What is the Role of Race and Ethnicity in the Development Of Thionamide-Induced Neutropenia?

Thionamides are anti-thyroid drugs (ATD) used to treat autonomous thyrotoxicosis. Although efficacious, these medications carry a risk of neutropenia or agranulocytosis. Some risk factors for ATD-induced neutropenia have been identified, including dose, age, and female sex, but the role of race and ethnicity has not been well studied. We hypothesize that there will be no effect of race or ethnicity on the change in Absolute Neutrophil Count (ANC) following initiation of ATD therapy. Data from the Electronic Medical Record at UNM HSC were obtained using a standard database query. Inclusion criteria were the prescription of an ATD, an ANC recorded within 30 days of initiating ATD therapy (Pre-ATD), and an ANC recorded 75 - 365 days after starting an ANC (Post-ATD). Patients taking other agents known to cause neutropenia were excluded. Racial and ethnic groups were assigned as follows: Hispanic, Non-Hispanic White, Native American, Black/African American, and Asian/Pacific Islander. Post-ATD ANC was defined as the nadir ANC after ATD initiation. "Delta ANC" was defined as ((Post-ATD ANC) - (Pre-ATD ANC)). ANOVA analysis with Bonferroni-adjusted post-hoc testing and multiple regression were performed to examine differences in the mean changes in ANC across ethnic groups. One hundred and twenty-three adult patients met inclusion and exclusion criteria and were included in the analysis. The Native American group showed a significantly greater Post-ATD ANC and Delta-ANC as compared to the other groups (p<0.001). In this cohort of New Mexicans with thyrotoxicosis, Native American race was protective against thionamide-induced neutropenia.

DOES PRE-OPERATIVE VITAMIN D DEFICIENCY PREDICT POSTOPERATIVE HYPOCALCEMIA AFTER THYROIDECTOMY?

OBJECTIVE: Postoperative hypocalcemia is frequent after total thyroidectomy. The role of pre-operative vitamin D levels in the pathogenesis of this condition has not been studied under the most current guidelines for evaluation of the role of vitamin D in calcium homeostasis. We hypothesized that patients who are vitamin D deficient (VDD) pre-operatively are more likely to suffer from postoperative hypocalcemia, thereby requiring prolonged hospitalization. METHODS: A retrospective chart review of patients undergoing total thyroidectomy at the University of New Mexico Hospital between 2005 and 2014 was performed. Patients who underwent intentional parathyroidectomy were excluded. The study included 30 patients who had a 25-hydroxyvitamin D levels obtained within 12 months before surgery. RESULTS: Twelve patients who were VDD (25-hydroxyvitamin D ≤20 ng/mL) were compared to 18 patients who did not have VDD (non-VDD; 25-hydroxyvitamin D >20 ng/mL). The mean nadir postoperative ionized calcium concentration was lower in the VDD group (0.99 ± 0.10 vs. 1.06 ± 0.06 mmol/L, P = .04) (reference range = 1.15-1.27 mmol/L), as was the postoperative concentration of phosphorus (3.48 ± 0.60 vs. 4.17 ± 0.84 mg/dL, P = .03). VDD patients had a longer length of stay (4.3 ± 4.4 vs. 1.7 ± 1.5 days, P = .03). Three patients in the VDD group required intravenous calcium for treatment of symptomatic hypocalcemia, but none of the non-VDD patients required this intervention (P = .054). CONCLUSION: Pre-operative vitamin D deficiency is associated with an increased risk of postoperative hypocalcemia and a prolonged length of stay in patients undergoing total thyroidectomy. Vitamin D replacement before thyroidectomy may improve postsurgical outcomes in VDD patients. ABBREVIATIONS: BMI = body mass index non-VDD = non-vitamin D deficient PTH = parathyroid hormone VDD = vitamin D deficient.

Association of passive and active smoking with pre-diabetes risk in a predominantly Hispanic population.

Smoking is the leading cause of avoidable death and is associated with type 2 diabetes (T2D) risk. Previous studies on the impact of passive smoking have not been applied to a Hispanic-majority population. We investigated the association between active smoking, exposure to environmental tobacco smoke (ETS), and pre-diabetes risk in a New Mexico population. We hypothesized that pre-diabetes risk increases with increasing smoking status after adjustment for important covariates. We screened 219 adults from an ongoing study who were categorized according to their smoking status (never smoker, current smoker, previous smoker) and their exposure to ETS (exposed or unexposed). Glucose homeostasis status was assigned using A1c: no diabetes (A1c <5.7%), pre-diabetes (A1c 5.7-6.4%), and T2D (A1c >6.4%). Among 160 patients with complete data, 51.6% had no diabetes and 48.4% had pre-diabetes. The mean age was 44.8±13.5 years. The study population was predominantly female (64.4%), and the ethnic composition was 44.4% Hispanic, 39.4% non-Hispanic White (NHW), 10.6% American Indian, 2.5% African-American, and 3.1% other. Using a logistic model with 2-way interactions, all predicted probabilities for being at risk for pre-diabetes were significant at the 0.001 level for smoking status and ETS exposure after adjusting for age, sex, ethnicity, family history of diabetes, alcohol consumption, BMI, and blood pressure. Active or passive smoking is independently associated with pre-diabetes risk.