ORIGINAL
E n d o c r i n e
ARTICLE
C a r e
Incidence and Prevalence of Primary
Hyperparathyroidism in a Racially Mixed Population
Michael W. Yeh, Philip H. G. Ituarte, Hui Cynthia Zhou, Stacie Nishimoto,
In-Lu Amy Liu, Avital Harari, Philip I. Haigh, and Annette L. Adams
Section of Endocrine Surgery (M.W.Y., P.H.G.I., S.N., A.H.), UCLA David Geffen School of Medicine, Los
Angeles, California 90095; Department of Research and Evaluation (H.C.Z., I.-L.A.L., A.L.A.), Kaiser
Permanente Southern California, Pasadena, California 91101; and Department of Surgery (P.I.H.), Kaiser
Permanente Los Angeles Medical Center, Los Angeles, California 90027
Context: The epidemiology of primary hyperparathyroidism (PHPT) has generally been studied in
Caucasian populations.
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Objective: The aim was to examine the incidence and prevalence of PHPT within a racially mixed
population.
Design: A descriptive epidemiologic study was performed.
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Patients/Setting: The study population included 3.5 million enrollees within Kaiser Permanente
Southern California.
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Methods: All patients with at least one elevated serum calcium level (⬎10.5 mg/dL, 2.6 mmol/L)
between 1995 and 2010 were included. Cases of PHPT were identified by electronic query of
laboratory values using biochemical criteria, after exclusion of secondary or renal and tertiary
hyperparathyroidism cases. The incidence and prevalence rates of PHPT were calculated according
to sex, race, age group by decade, and year.
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Results: Initial case finding identified 15,234 patients with chronic hypercalcemia, 13,327 (87%) of
which had PHPT as defined by elevated or inappropriately normal parathyroid hormone levels. The
incidence of PHPT fluctuated from 34 to 120 per 100 000 person-years (mean 66) among women,
and from 13 to 36 (mean 25) among men. With advancing age, incidence increased and sex differences became pronounced (incidence 12–24 per 100 000 for both sexes younger than 50 y; 80
and 36 per 100 000 for women and men aged 50 –59 y, respectively; and 196 and 95 for women and
men aged 70 –79 y, respectively). The incidence of PHPT was highest among blacks (92 women; 46
men, P ⬍ .0001), followed by whites (81 women; 29 men), with rates for Asians (52 women, 28 men),
Hispanics (49 women, 17 men), and other races (25 women, 6 men) being lower than that for whites
(P ⬍ .0001). The prevalence of PHPT tripled during the study period, increasing from 76 to 233 per
100 000 women and from 30 to 85 per 100 000 men. Racial differences in prevalence mirrored those
found in incidence.
Conclusions: PHPT is the predominant cause of hypercalcemia and is increasingly prevalent. Substantial differences are found in the incidence and prevalence of PHPT between races. (J Clin
Endocrinol Metab 98: 1122–1129, 2013)
ISSN Print 0021-972X ISSN Online 1945-7197
Printed in U.S.A.
Copyright © 2013 by The Endocrine Society
Received November 27, 2012. Accepted January 7, 2013.
First Published Online February 15, 2013
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Abbreviations: KPSC, Kaiser Permanente Southern California; PHPT, primary hyperparathyroidism; PTH, parathyroid hormone.
J Clin Endocrinol Metab, March 2013, 98(3):1122–1129
doi: 10.1210/jc.2012-4022
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Patients with classic PHPT were defined as those with hypercalcemia (serum calcium greater than 10.5 mg/dL) and parathyroid hormone (PTH) excess (PTH greater than 65 pg/mL [6.8
pmol/L]; normal 15– 65). Patients with nonclassic PHPT were
defined as those with hypercalcemia (serum calcium greater than
10.5 mg/dL) and inappropriately normal or nonsuppressed PTH
levels ranging from 21 to 65 pg/mL. Patients not meeting either
of these PTH criteria were followed up forward in time for a
second high serum calcium level within 3 to 24 months to confirm chronic hypercalcemia. Patients with only a single high calcium level were considered spurious cases and excluded. Additional exclusions were applied to patients with a history of
invasive cancer at any time before or within 24 months after the
index high calcium date, those with a history of thiazide diuretic
use (hydrochlorothiazide, chlorothiazide, chlorthalidone, metolazone, indapamide, methyclothiazide, alone or in combination)
at any time before or within 24 months after the index high
calcium date, and those with documented low PTH values less
than 21 pg/mL. Invasive cancer diagnoses were determined using
International Classification of Diseases, Ninth Revision, Clinical
Modification (ICD-9-CM) codes 140 to 209 and 235 to 239 to
encompass neoplasms of undetermined behavior or pathology.
The remaining patients with chronic hypercalcemia, unknown
PTH levels, and no thiazide use or invasive cancer were considered cases of possible PHPT.
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rimary hyperparathyroidism (PHPT) is a relatively
common endocrine disorder, with prevalence estimates of one to seven cases per 1000 adults (1– 4). It is
believed to be the most common cause of hypercalcemia,
predominantly affecting elderly populations and women
two to three times as often as men (5). To date, reports on
the epidemiology of PHPT have been derived from geographic locations populated predominantly by Caucasian
individuals, such as Sweden, Norway, Finland, Scotland,
and Rochester, Minnesota. Therefore, such data may not
accurately reflect patterns of disease across the racially
diverse United States.
The incidence of PHPT has been difficult to assess.
Available estimates vary widely from 0.4 to 21.6 cases per
100 000 person-years (4, 6). This variation arises from
heterogeneity in screening methods, case definitions, the
populations studied, and annual fluctuations in incidence
within the same population that remain unexplained.
The aim of the current study is to determine the incidence and prevalence of PHPT in a racially mixed population by applying a uniform biochemical algorithm.
Race- and age-related differences in incidence and prevalence are examined.
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Defining age, sex, and race
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After case identification, laboratory data were linked to demographic information within the KPSC discharge abstract database. Adult women and men 20 years or older were included
in the sample. Age ranged from 20 to 99 years. To study age
differences in incidence and prevalence, seven age groups were
created (20 –29, 30 –39, 40 – 49, 50 –59, 60 – 69, 70 –79, ⬎80 y).
Patients were classified by race and ethnicity as Asian, black,
Hispanic, and white. The category “other” was used to include
patients whose race or ethnicity were coded as “other” or who
did not provide any information.
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Subjects and Methods
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Study population
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The study population included all active enrollees in Kaiser
Permanente Southern California (KPSC), an integrated health
care delivery system serving approximately 3.5 million subscribers, representing 20% of the insured population in the
region. The KPSC membership closely mirrors the population
of the greater Los Angeles metropolitan area demographically
and socioeconomically, except for the extremes of the income
distribution (7, 8). Because most members receive employerbased insurance benefits, outmigration rates are low, with
two-thirds of subscribers maintaining membership for 5 years
or more.
Case definitions
After approval from the KPSC institutional review board, the
Kaiser Permanente Medical Center laboratory management system was queried electronically to identify patients with a biochemical diagnosis of PHPT during the years 1995 through
2010. A three-level algorithm was employed to identify cases of
PHPT strictly by biochemical criteria. Initial case finding was
performed by identifying all patients with at least one elevated
calcium level (serum calcium greater than 10.5 mg/dL [2.6
mmol/L ]; normal 8.5–10.5). Initial exclusions were applied to
patients with membership terms of less than 6 mo, those younger
than 20 y, and those with secondary (renal) hyperparathyroidism
(serum creatinine greater than 2.5 mg/dL [221.0 mmol/L]). Any
patient who had at least two separate blood samples drawn for
cyclosporine, tacrolimus, or sirolimus levels was considered a
likely kidney transplant recipient with possible tertiary hyperparathyroidism and was excluded.
Statistical analysis
For each year, incidence was defined as the number of PHPT
cases per year divided by number of KPSC enrollees for the same
year. Cases were selected into a given year based on the index
date (date of initial high calcium level). The ratio of PHPT in
women to men has been reported to range from 2:1 to 3:1 (6).
Consequently, to avoid an averaging effect that would yield figures applicable to neither sex, crude and age-adjusted incidence
rates were calculated separately for women and men. Within
each gender, annual rates were also calculated by race and by age
group. Age-adjusted incidence was estimated by applying population data from the 2000 US Census (9). Confidence intervals
for incidence were assumed to follow a Poisson distribution and
were estimated by applying appropriate correction factors (10).
Once cases were categorized into classic, nonclassic, or possible PHPT, prevalence rates were calculated by tracking biochemical values over time. As long as a given case continued to
have high serum calcium levels over the course of the patient’s
KPSC membership, the case was included as part of the annual
prevalence of PHPT. Prevalence was censored for a case once a
patient received a curative parathyroidectomy, had no high calcium levels recorded in a given year, was no longer actively enrolled in KPSC, or died. Prevalence rates used the same denom-
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Primary Hyperparathyroidism Incidence
J Clin Endocrinol Metab, March 2013, 98(3):1122–1129
Table 1. Demographics of Kaiser Permanente Southern
California Population, 1995–2010
KPSC
Sample
Population
Sex
Women
Men
Race
Asian
Black
Hispanic
Other
White
N (Mean)
N (Range)
%
1 760 386
1 179 690 –2 135 390
100.0
947 754
812 632
771 767–1 006 511
407 929 –1 037 794
53.8
46.2
87 373
153 991
466 912
405 727
646 383
27 097–116 895
124 502–179 284
185 233– 672 078
192 576 – 620 309
592 011–703 725
5.0
8.8
26.5
23.0
36.7
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inator as incidence. Crude and age-adjusted prevalence rates
were calculated, and confidence intervals were estimated assuming a binomial distribution.
female and 63.3% nonwhite (Table 1). The mean intact
PTH level in the classic PHPT group was 128.2 pg/mL
compared with 40.0 pg/mL in the nonclassic PHPT group
(Table 2). Despite the large difference in the PTH levels,
the serum calcium levels were only slightly higher in the
classic PHPT group (11.2 vs 10.9 mg/dL).
Initial case finding yielded 57 132 subjects with at least
one elevated serum calcium level during the study period
(Figure 1), of which 40 857 were eligible for inclusion. Of
the 13 327 with documented high or normal PTH levels,
6868 were categorized as having classic PHPT (PTH ⬎ 65
pg/mL) and 6459 were categorized as having nonclassic
PHPT (PTH 21– 65 pg/mL). All of these patients had
chronic hypercalcemia as defined by multiple instances of
high serum calcium on different dates. Of the 27 530 patients without documented high or normal PTH levels,
25 623 were spurious cases with no additional episodes of
hypercalcemia within 3 to 24 months of the index high
calcium date. Additional exclusions were applied to the
1907 remaining patients with chronic hypercalcemia,
1479 of whom had non-PHPT hypercalcemia as explained
by invasive cancer, thiazide diuretic use, or a documented
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The KPSC population grew from 1 179 690 to 2 044 305
members from 1995 to 2010. The population was 53.8%
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Results
Age,
Mean (SD)
Serum Calcium (mg/dL),
Mean (SD)
Intact PTH (pg/mL),
Mean (SD)
6868 (100.0)
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11.2 (0.7)
128.2 (86.3)
64.7 (12.8)
61.9 (14.8)
11.3 (0.6)
11.2 (0.8)
125.7 (82.6)
136.9 (97.3)
or
N (%)
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5311 (77.3)
1,557 (22.7)
64.0 (13.4)
335 (4.9)
1191 (17.3)
1054 (15.3)
415 (6.1)
3873 (56.4)
60.5 (12.8)
64.2 (12.6)
58.9 (14.2)
61.0 (13.4)
66.0 (12.9)
11.2 (0.6)
11.2 (0.7)
11.2 (0.7)
11.1 (0.5)
11.1 (0.7)
132.5 (96.7)
137.9 (99.1)
124.5 (102.8)
118.8 (66.9)
122.0 (76.7)
6459 (100.0)
62.3 (13.8)
10.9 (0.5)
40.0 (12.4)
5054 (78.2)
1405 (21.8)
63.9 (12.8)
56.7 (15.8)
10.9 (0.5)
11.0 (0.5)
40.2 (12.4)
39.2 (12.3)
409 (6.3)
681 (10.5)
694 (10.7)
615 (9.5)
4060 (62.9)
60.3 (13.4)
61.4 (13.2)
57.7 (14.9)
56.0 (14.0)
64.4 (13.2)
10.9 (0.3)
11.0 (0.6)
11.0 (0.6)
10.9 (0.3)
10.9 (0.5)
38.3 (12.7)
42.0 (12.8)
40.5 (12.5)
39.8 (12.1)
39.8 (12.3)
452 (100.0)
57.0 (17.6)
10.9 (0.4)
287 (63.5)
165 (36.5)
59.6 (17.9)
52.6 (16.2)
10.9 (0.4)
10.9 (0.4)
28 (6.2)
61 (13.5)
93 (20.6)
34 (7.5)
234 (51.8)
52.9 (17.9)
52.3 (15.6)
50.1 (16.7)
49.8 (16.3)
62.7 (16.6)
10.8 (0.2)
10.9 (0.4)
10.9 (0.4)
10.8 (0.3)
10.9 (0.4)
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Classic PHPT
Total
Gender
Women
Men
Race
Asian
Black
Hispanic
Other
White
Nonclassic PHPT
Total
Gender
Women
Men
Race
Asian
Black
Hispanic
Other
White
Possible PHPT
Total
Gender
Women
Men
Race
Asian
Black
Hispanic
Other
White
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Table 2. Demographic and Biochemical Features of Primary Hyperparathyroidism Cases
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Figure 1. Case definitions. PHPT, primary hyperparathyroidism; PTH, parathyroid hormone. Normal PTH 21 to 65 pg/mL (2.2– 6.8 pmol/L).
low PTH level of less than 21 pg/mL. Unexplained chronic
hypercalcemia was found in 428 patients with unknown
PTH levels, and these patients were categorized as having
possible PHPT.
The age-adjusted incidence of PHPT (classic, nonclassic, and possible combined) fluctuated between 34.0 and
120.2 in women and 13.4 and 35.6 in men, with an average incidence of 65.5 and 24.7 over the entire study
period for women and men, respectively (Figure 2). The
incidence of classic PHPT ranged from 17.6 to 48.5 per
100 000 person-years among women, and from 7.2 to
20.9 per 100 000 person-years among men (Supplemental
Table 1). (Please see Supplemental Table 1 published on
The Endocrine Society’s Journals Online web site at http://
jcem.endojournals.org.) The incidence of nonclassic
PHPT varied from 12.6 to 72.2 per 100 000 person-years
among women and from 4.0 to 15.8 per 100 000 personyears among men. The incidence of possible PHPT was
relatively low, ranging from one to eight cases per 100 000
person-years for both women and men. Over the 15-year
period, the incidence of PHPT was consistently higher
among women than men, with an incidence ratio ranging
from 1.8 to 4.0 (mean incidence ratio 2.7).
The proportion of KPSC enrollees with at least one
serum calcium test drawn per year grew steadily from
6.8% in 1995 to 12.7% in 2010 for women, and from
5.3% to 8.9% in men (Supplemental Table 1); this figure
did not correlate with the incidence of PHPT in the population for either sex. We noted racial differences in the
proportion of patients with at least one calcium test per
year, with the black women having the highest rate of
calcium testing (13.0%), followed by whites (12.9%),
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Figure 2. Age-adjusted incidence of primary hyperparathyroidism by year, women and men. PHPT, primary hyperparathyroidism.
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lower than that for whites (P ⬍ .0001). Racial differences
also became more pronounced among older patients.
The age-adjusted prevalence of PHPT climbed from
76.3 to 232.7 per 100 000 among women, and from 29.5
to 85.2 per 100 000 among men during the study period
(Figure 4, Supplemental Table 3). This growth was almost
entirely attributable to an increase in the prevalence of
classic PHPT. The prevalence ratio of female-to-male
cases remained stable at approximately 2.5 to 1 when all
age groups and races were considered together.
Prevalence rates were then analyzed separately according to sex, race, and age by decade (Figure 5, Supplemental
Table 4). The prevalence of PHPT rose with increasing
age, peaking at an average of 492.2 per 100 000 women
aged 70 –79 years and 264.1 per 100 000 men aged
80 years or older. PHPT was most prevalent among older
blacks, affecting 921.5 per 100 000 black women aged
70 –79 y (vs 630.3 per 100 000 in similarly aged whites,
P ⬍ .0001), and 481.1 per 100 000 black men aged
80 years or older (vs 164.7 per 100 000 in similarly aged
whites, P ⬍ .0001).
Because prevalence rates tripled over the study period,
the year 2010 was analyzed separately to provide a reflection of the present (Supplemental Table 5). The highest
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Asians (9.1%), Hispanics (7.7%), and other (4.2%; P ⬍
.0001). A similar pattern was observed among men, with
blacks having the highest rate of calcium testing (11.9%),
followed by whites (10.4%), Asians (8.8%), Hispanics
(6.4%), and other (2.3%; P ⬍ .0001). These differences in
the frequency of calcium testing did not correlate with
race-specific PHPT incidence rates.
Incidence rates were analyzed separately according to
sex, race, and age group by decade (Figure 3, Supplemental Table 2). For those younger than 50 years, incidence
rates were generally low and similar across the sexes (incidence 12.1–24.4 per 100 000 person-years, all races).
With advancing age, incidence increased and sex differences became pronounced. For patients 50 –59 years, the
incidence was 79.6 per 100 000 person-years for women
and 35.6 per 100 000 person-years for men (all races). For
patients 70 –79 years, the incidence was 195.7 per
100 000 person-years for women and 94.6 per 100 000
person-years for men (all races).
The age-adjusted incidence of PHPT was highest
among blacks (92.0 women; 46.0 men, P ⬍ .0001) followed by whites (81.0 women; 29.4 men), with rates for
Asians (51.8 women, 27.9 men), Hispanics (48.6 women,
17.1 men), and other races (25.4 women, 5.9 men) being
Figure 3. Incidence of primary hyperparathyroidism (crude) by race and age group, all years, women and men. PHPT, primary
hyperparathyroidism.
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Figure 4. Age-adjusted prevalence of primary hyperparathyroidism by year, women and men. PHPT, primary hyperparathyroidism.
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amined populations comprised of 90% or more white individuals. We believe that our findings are reflective of the
larger US population.
The large sample size has allowed us to calculate incidence and prevalence rates split along the three axes of sex,
race, and age by decade, while maintaining adequate statistical power to make intergroup comparisons. Previously, the most frequently reported statistic on PHPT incidence in the United States was 21.6 cases per 100 000
person-years, as calculated from an analysis of residents of
Rochester, Minnesota (6). We found that the incidence of
PHPT fluctuated between 36.3 and 120.2 in women and
13.4 and 35.6 in men, with an average incidence of 65.5
and 24.7 over the entire study period for women and men,
respectively. Similar fluctuations in incidence have been
observed in other studies (3, 4) and remain unexplained.
The fluctuations we observed did not correlate with the
frequency of calcium testing, which increased steadily during the study period across all sex, race, and age groups.
Most European studies have reported relatively low incidence rates of less than 6 per 100 000 person-years (12,
13). One study examining residents of Tayside, Scotland,
reported slightly higher incidence rates of 57.8 to 146.0
per 100 000 person-years for women and 22.8 to 79.5 per
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age-adjusted prevalence rates during that year remained in
black women (447.9 per 100 000), followed by whites
(312.0), Asians (183.7), Hispanics (169.4), and other
(46.2). The same pattern was observed among men, with
black men having the highest age-adjusted prevalence of
177.5 per 100 000, followed by whites (103.1), Asians
(71.8), Hispanics (54.8), and other (12.0) The highest
overall prevalence rate found in the study was 1408.9,
representing black women aged 70 –79 years in 2010.
Vitamin D levels were available in 30% of subjects
(Supplemental Table 6). Rates of vitamin D deficiency (as
defined by a 25-hydroxy vitamin D level ⬍ 20 ng/mL) were
lowest among whites (11.3%) and Asians (11.3%) and
highest among blacks (30.9%, P ⫽ .004).
The current study, encompassing 13 779 patients with
PHPT, is the largest such series reported to our knowledge.
Previously published series have included as many as 9782
patients in Europe (4, 11, 12) and 475 patients in the
United States (3). We have described racial differences in
the incidence and prevalence of PHPT, something not previously achievable because all previous studies have ex-
Figure 5. Prevalence of primary hyperparathyroidism (crude) by race and age group, all years, women and men. PHPT, primary
hyperparathyroidism.
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Primary Hyperparathyroidism Incidence
J Clin Endocrinol Metab, March 2013, 98(3):1122–1129
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referred for surgery, despite usually having hypercalcemia
of a degree similar to that of patients with classic PHPT.
This large group of patients merits clinical attention and
further characterization in the literature.
Unique to our study is the strictly biochemical algorithm of identifying PHPT cases, which carries numerous
strengths and several weaknesses. Previous epidemiologic
studies have captured cases using a combination of biochemical, histopathologic, radiologic, and clinical data
sources (1, 3, 4, 12, 13, 22), likely because the biochemical
data may have been less broadly available in these study
settings than in ours. PHPT is fundamentally a biochemical disease; establishing the diagnosis hinges entirely on
demonstration of inappropriate PTH excess, and confirmation of surgical cure rests entirely on demonstration of
having appropriate PTH levels restored. All other data
sources carry considerable ascertainment bias. Histopathologic data would yield a higher detection rate for the
minority of patients treated surgically. Furthermore, histopathologic evidence of parathyroid adenomas can be
found incidentally in eucalcemic individuals undergoing
thyroidectomy; these patients cannot be considered to
have PHPT (23). Radiologic studies have sensitivities and
specificities that are far from 100%; there is consensus that
imaging is not an appropriate method of diagnosing PHPT
(24). Clinical data would rely upon the skill of the physician and his or her attentiveness to the diagnosis of PHPT,
which is highly variable (14).
Although our algorithm was designed to be highly sensitive, the priority was specificity, that is, avoidance of
sample contamination with non-PHPT cases. Thus, we
may have slightly underestimated the incidence and prevalence of PHPT by excluding the following types of patients: those with PHPT and renal impairment (serum creatinine ⬎2.5 mg/dL), those with PHPT who are also
taking a thiazide diuretic, and those with PHPT and a
history of invasive cancer. In fact, because hypercalcemia
is an uncommon complication of malignancy, it is likely
that most patients we excluded using the invasive cancer
criterion actually had PHPT (25). Because urine calcium
measurements were available only in a minority of subjects, we acknowledge that our sample may be contaminated with a small number of patients with familial hypocalciuric hypercalcemia, which has an estimated
prevalence of 1 in 78,000 (26). The small population of
patients with possible PHPT may be contaminated with a
few patients with non-PHPT hypercalcemia of uncommon
origin, such as hypervitaminosis D, milk-alkali syndrome,
thyroid dysfunction, or sarcoidosis (20). It is important to
note that our population is completely covered by private
health insurance and thus unaffected by biases related to
access to care. For these reasons, we believe our incidence
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100 000 person-years for men, figures that parallel our
findings.
The prevalence of PHPT increased by a factor of 3.05
in women and 2.89 in men over the study period. We
attribute this growth to the accumulation of cases through
routine calcium testing; annual biochemical monitoring of
patients with classic PHPT, which ensures retention
within the cohort; and a relatively low rate of exit through
surgical treatment. We have documented previously that
28% of patients with PHPT undergo surgery (14). The age
and gender distribution of our cohort remained stable over
the study period.
We have discovered substantial racial differences in the
incidence and prevalence of PHPT, with the highest rates
observed consistently in older black women. This finding
raises a series of questions that have been altogether unexplored, most notably, do blacks therefore experience the
adverse health effects of PHPT more commonly than do
other races? Black American physiology is characterized
by higher PTH levels, lower vitamin D levels, and a reduced risk of osteoporotic fracture compared with those
of other races (15–18). These distinctive features of calcium homeostasis in this racial group have raised questions regarding whether the established normal range for
vitamin D is appropriate for blacks (19).
Our study has a number of other salient findings. Although PHPT is acknowledged to be the most common
cause of hypercalcemia in ambulatory patients (20), our
ability to electronically identify all elevated calcium levels
has led to the discovery that 90% of all chronic hypercalcemia is attributable to PHPT. This remarkably high proportion serves as a reminder that all patients with hypercalcemia should have their PTH levels measured because
heightened attention to this diagnosis may yield opportunities for fracture prevention. We also found that, of patients with PHPT, only half have the classic form of the
disease, characterized by elevations of both serum calcium
and PTH. The remaining half represent nonclassic cases
with high serum calcium and inappropriately normal or
nonsuppressed PTH levels. In principle, the distinction
between the two is artificial because both forms of the
disease are characterized by inappropriate PTH excess and
follow the same demographic patterns. However, in clinical practice we have observed considerable confusion regarding nonclassic PHPT cases. Patients with classic
PHPT were closely monitored with annual calcium testing, which was responsible for the steady increase in the
prevalence of these cases; they also commonly underwent
bone mineral density measurement as recommended by
consensus guidelines (21). In contrast, patients with nonclassic PHPT were inconsistently monitored, rarely underwent bone density measurement, and very rarely were
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doi: 10.1210/jc.2012-4022
jcem.endojournals.org
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Address all correspondence and requests for reprints to: Michael
W. Yeh, Associate Professor of Surgery and Medicine (Endocrinology), Chief, Section of Endocrine Surgery, 10833 Le Conte
Avenue, 72-228 CHS, Box 956904, Los Angeles, California
90095. E-mail: [email protected].
Annette L. Adams had full access to all the data in the study
and takes responsibility for the integrity of the data and the
accuracy of the data analysis.
This study was approved by the Institutional Review Boards
of both UCLA David Geffen School of Medicine and Kaiser
Permanente Southern California.
This study was supported by the National Institutes of
Health/National Institute on Aging (RFA-AG-11-007), the
American Geriatrics Society, and the Earl Gales Family
Foundation.
Disclosures: The authors have no conflicts of interest to
disclose.
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Acknowledgments
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or
and prevalence figures are as objective and unbiased as
possible.
In conclusion, we have identified the largest population-based cohort of patients with PHPT described to date
and have documented racial differences in the incidence
and prevalence of PHPT for the first time. Given that published longitudinal series on the long-term effects of this
disease have involved relatively low sample sizes, additional study of this cohort should shed light on the natural
history of PHPT and the effectiveness of different management strategies on long-term skeletal and extraskeletal
outcomes. Moreover, additional study regarding racial
differences in the biochemical and clinical manifestations
of this disease is warranted.
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