SAN DIEGO – Depression and subclinical cardiovascular abnormalities in patients with primary hyperparathyroidism are emerging as two novel indications for parathyroidectomy.
Primary hyperparathyroidism is no longer typically characterized by the classic florid manifestations involving metabolic bone disease, GI disturbances, and nephrolithiasis. In an era of routine serum calcium measurement, most affected patients are largely asymptomatic, or they report nonspecific symptoms involving mood, cognition, and neuromuscular function.
Studies presented at the annual meeting of the American Society for Bone and Mineral Research indicate that clinically significant depression is more frequent and severe in patients with primary hyperparathyroidism, and subclinical cardiovascular abnormalities are more common as well.
Moreover, investigators presented evidence that both conditions respond favorably to parathyroidectomy. The clear implication for clinical practice, according to the presenters, is that assessment for depression as well as a cardiovascular evaluation including carotid ultrasound and an echocardiogram should become part of the routine evaluation of patients with primary hyperparathyroidism (PHP). Positive findings may be an appropriate indication for parathyroidectomy in patients who otherwise don’t meet the surgical criteria.
Depression
Dr. Rachel Espiritu presented a prospective, nonrandomized, case-control study involving 169 patients with PHP and 85 controls with benign, nontoxic forms of thyroid disease. At baseline, 88 PHP patients underwent parathyroidectomy, while the other 81 were observed for the yearlong study period. The controls with benign thyroid disease underwent thyroidectomy at baseline.
The validated Patient Health Questionnaire–9 (PHQ-9) was used to identify subjects with clinically significant depression. All study participants took the test at baseline and at 1, 3, 6, and 12 months. The three groups were similar in terms of history of depression, use of antidepressant medications, and experience with psychotherapy.
Average baseline PHQ-9 scores were significantly higher in the 169 patients with PHP than in controls by a margin of 1.71 points out of the theoretically possible 27. Major depression, as defined by a score of 10 or more, was twice as common in the PHP patients, with a baseline prevalence of 31% compared with 15% in the thyroid disease group. The PHP patients who had a baseline serum calcium of 11 mg/dL or higher had a median PHQ-9 score of 9 compared with 4 in those with a lower calcium level.
Parathyroidectomy resulted in a large, durable reduction in PHQ-9 scores. The scores dropped by an age- and gender-adjusted average of 64% 1 month post surgery, with a 66% reduction at 1 year compared with baseline, reported Dr. Espiritu of the Mayo Clinic, Rochester, Minn.
A PHQ-9 score of 10 or greater was present at baseline in 43% of the parathyroidectomy group. The prevalence plunged to 7% at 1 month post surgery and remained there at 1 year. In contrast, the prevalence of scores of 10-plus remained unchanged over the course of the year in the 81 PHP patients in the observation arm.
PHQ-9 scores also declined following thyroidectomy in the control group. But the reductions were significantly greater in the parathyroidectomy group at every time point.
Dr. Espiritu concluded that a PHQ-9 score of 10 or more or ongoing depression in a patient with PHP warrants consideration of parathyroid surgery.
Cardiovascular Abnormalities
Dr. Marcella Walker reported on 44 patients with mild hyperparathyroidism who underwent carotid ultrasound and echocardiographic studies before postparathyroidectomy and 12 and 24 months afterward.
Selected subclinical cardiovascular abnormalities present at baseline improved and often normalized during the second year of follow-up. Increased carotid stiffness, present in 17 of 44 patients at baseline, normalized in 8 patients and decreased without reaching normal range to a lesser extent in the others. Increased intima-media thickness, present in 32 patients at baseline, declined from an average of 0.99 mm at baseline to 0.97 mm 2 years later.
Diastolic dysfunction, as defined by an abnormal early to late mitral annular velocity ratio, was present in 11 patients at baseline and normalized postsurgically in all cases. Similarly, another indicator of diastolic dysfunction – an elevated intravascular relaxation time – was identified in eight patients preoperatively, all of whom improved to within normal range post parathyroidectomy, according to Dr. Walker of Columbia University, New York.
On the other hand, baseline abnormalities in left ventricular mass index remained unchanged following surgery. Nor was any improvement seen in maximal carotid plaque thickness or carotid plaque number, she noted.
The changes noted in cardiovascular parameters following parathyroidectomy can’t be attributed to reductions in blood pressure or body mass index, as both parameters remained unaltered during the 2-year study period.
No financial conflicts of interest were reported.