A New, Vitamin D-Based, Multidimensional Nomogram for the Diagnosis of Primary Hyperparathyroidism

Adrian Harvey, MD; MengJun Hu, MS; Manjula Gupta, PhD; Robert Butler, MS; Jamie Mitchell, MD; Eren Berber, MD; Allan Siperstein, MD; Mira Milas, MD, FACS


Endocr Pract. 2012;18(2):124-131. 

In This Article


In summary, a significant proportion of patients with 1°HPT may have borderline laboratory results, which may present a diagnostic dilemma. The traditional, 2-dimensional nomogram with use of serum calcium and PTH levels may be inadequate for the assessment of such patients. As a result, patients may be misdiagnosed, need additional tests, or require follow-up with repeated blood studies in order to clarify the diagnosis. In the current study, we used mathematical modeling to develop a multidimensional nomogram in order to create patient-specific reference standards for PTH. This nomogram should not be confused as a model that predicts or calculates all 3 biochemical variables—calcium, PTH, and 25(OH)D levels. Rather, the nomogram provides a more biologically sensitive estimation of what PTH (and only PTH) ought to be, in light of the actual blood test measurements of serum calcium and 25(OH)D that physiologically regulate PTH release. Comparison of the estimated PTH from the nomogram with the actually measured serum PTH level can assist a clinician in thinking about patients with parathyroid diseases, especially when they do not conform to an easy diagnostic category. Application of our model to a retrospective series of patients with surgically proven parathyroid disease yielded promising results. This model deserves prospective validation and could potentially be modified through consideration of additional predictive variables and use of ionized calcium measurements.


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