Publications

The objective was to determine whether automated telephone self-management support (ATSM) for low-income, linguistically diverse health plan members with diabetes affects health care utilization or cost. A government-sponsored managed care plan for low-income patients implemented a demonstration project between 2009 and 2011 that involved a 6-month ATSM intervention for 362 English-, Spanish-, or Cantonese-speaking members with diabetes from 4 publicly funded clinics. Participants were randomized to immediate intervention or a wait-list. Medical and pharmacy claims used in this analysis were obtained from the managed care plan. Medical claims included hospitalizations, ambulance use, emergency department visits, and outpatient visits. In the 6-month period following enrollment, intervention participants generated half as many emergency department visits and hospitalizations (rate ratio 0.52, 95% CI 0.26, 1.04) compared to wait-listed participants, but these differences did not reach statistical significance (P=0.06). With adjustment for prior year cost, intervention participants also had a nonsignificant reduction of $26.78 in total health care costs compared to wait-listed individuals (P=0.93). The observed trends suggest that ATSM could yield potential health service benefits for health plans that provide coverage for chronic disease patients in safety net settings. ATSM should be further scaled up to determine whether it is associated with a greater reduction in health care utilization and costs.

CONTEXT

Calcium metabolism changes in pregnancy and lactation to meet fetal needs, with increases in 1,25-dihydroxyvitamin D [1,25-(OH)2D] during pregnancy playing an important role. However, these changes rarely cause maternal hypercalcemia. When maternal hypercalcemia occurs, further investigation is essential, and disorders of 1,25-(OH)2D catabolism should be carefully considered in the differential diagnosis.

CASE

A patient with a childhood history of recurrent renal stone disease and hypercalciuria presented with recurrent hypercalcemia and elevated 1,25-(OH)2D levels during pregnancy. Laboratory tests in the fourth pregnancy showed suppressed PTH, elevated 1,25-(OH)2D, and high-normal 25-hydroxyvitamin D levels, suggesting disordered vitamin D metabolism. Analysis revealed low 24,25-dihydroxyvitamin D3 and high 25-hydroxyvitamin D3 levels, suggesting loss of function of CYP24A1 (25-hydroxyvitamin-D3-24-hydroxylase). Gene sequencing confirmed that she was a compound heterozygote with the E143del and R396W mutations in CYP24A1.

CONCLUSIONS

This case broadens presentations of CYP24A1 mutations and hypercalcemia in pregnancy. Furthermore, it illustrates that patients with CYP24A1 mutations can maintain normal calcium levels during the steady state but can develop hypercalcemia when challenged, such as in pregnancy when 1,25-(OH)2D levels are physiologically elevated.