Prevalence of monoclonal gammopathy of undetermined significance among men in Ghana.
OBJECTIVE
To determine the prevalence of monoclonal gammopathy of undetermined significance (MGUS), a precursor of multiple myeloma (MM), in Ghanaian men vs white men and to test for evidence to support an underlying race-related predisposition of the 2-fold higher prevalence of MGUS in African Americans vs whites.


METHODS
Between September 1, 2004, and September 30, 2006, 917 men (50-74 years) underwent in-person interviews and physical examinations. Serum samples from all participants were analyzed by electrophoresis performed on agarose gel; any serum sample with a discrete or localized band was subjected to immunofixation. Age-adjusted and standardized (to the 2000 world population) prevalence estimates of MGUS and 95% confidence intervals (CIs) were computed in the Ghanaian men and compared with MGUS prevalence in 7996 white men from Minnesota. Associations between selected characteristics and MGUS prevalence were assessed by the Fisher exact test and logistic regression models.


RESULTS
Of the 917 study participants, 54 were found to have MGUS, yielding an age-adjusted prevalence of 5.84 (95% CI, 4.27-7.40) per 100 persons. No significant variation was found by age group, ethnicity, education status, or prior infectious diseases. The concentration of monoclonal immunoglobulin was undetectable in 41 (76%) of the 54 MGUS cases, less than 1 g/dL in 10 patients (19%), and 1 g/dL or more in only 3 patients (6%). Compared with white men, the age-adjusted prevalence of MGUS was 1.97-fold (95% CI, 1.94-2.00) higher in Ghanaian men.


CONCLUSIONS
The prevalence of MGUS in Ghanaian men was twice that in white men, supporting the hypothesis that race-related genetic susceptibility could explain the higher rates of MGUS in black populations. An improved understanding of MGUS and MM pathophysiology would facilitate the development of strategies to prevent progression of MGUS to MM.
Landgren
Ola
O
Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 6120 Executive Blvd, Bldg. EPS/Room 7110, Bethesda, MD 20892-7236, USA. landgreo@mail.nih.gov
Katzmann
Jerry A
JA
Hsing
Ann W
AW
Pfeiffer
Ruth M
RM
Kyle
Robert A
RA
Yeboah
Edward D
ED
Biritwum
Richard B
RB
Tettey
Yao
Y
Adjei
Andrew A
AA
Larson
Dirk R
DR
Dispenzieri
Angela
A
Melton
L Joseph
LJ
Goldin
Lynn R
LR
McMaster
Mary L
ML
Caporaso
Neil E
NE
Rajkumar
S Vincent
SV
D017677:Age Distribution; D000368:Aged; D044383:Black People / Q000706:statistics & numerical data*; D020022:Genetic Predisposition to Disease; D005869:Ghana / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D010265:Paraproteinemias / Q000453:epidemiology*; D015995:Prevalence; D012959:Socioeconomic Factors; D044465:White People / Q000706:statistics & numerical data; D001741:Black or African American