May 8, 2007 — In nondiabetic women, menopause, but not age, is an
independent risk factor for elevated fasting plasma glucose levels,
according to the results of a study published in the May-June issue of
Menopause.
"Glucose metabolism is influenced by various genetic and
environmental factors," write Michio Otsuki, MD, from the Osaka University
Graduate School of Medicine in Osaka, Japan, and colleagues. "In women the
prevalence of abnormal glucose metabolism is known to increase around and
after age 50. The aim of this study was to determine whether menopause
augments fasting plasma glucose (FPG) levels in women."
Of 672 women in Japan undergoing health examinations, 505 did not have
diabetes, had no history of hysterectomy, and had never used estrogens or
progestins. All participants underwent an oral glucose tolerance test and
recording of blood measurements and provided information about their
menopausal status.
Of the 505 women, 208 were premenopausal and 297 were postmenopausal.
Age, body mass index (BMI), triglyceride level, total cholesterol level,
low-density lipoprotein (LDL) cholesterol level, blood pressure, and
homeostasis model assessment insulin sensitivity index increased across
quintiles of FPG levels. However, high-density lipoprotein (HDL) cholesterol
level and homeostasis model assessment pancreatic β-cell function index were
not correlated with FPG levels.
The number of premenopausal women decreased and the number of
postmenopausal women increased across quintiles of FPG levels. Age, BMI,
triglyceride level, LDL cholesterol level, and menopausal status were
associated with FPG level, but HDL cholesterol level was not, based on
univariate regression analysis. Independent risk factors for elevated FPG
levels, based on stepwise multivariate regression analysis, were BMI,
menopause, and triglyceride level, but age and LDL cholesterol level did not
contribute to FPG levels.
"Menopause, but not age, is directly involved in augmented FPG levels in
nondiabetic women," the authors write.
Study limitations include cross-sectional design and relatively small
sample size.
"Although there are gender differences in the development of diabetes,
gender-specific therapies for the prevention of diabetes and its vascular
complications have not yet been developed," the authors conclude.
"Therapeutic approaches taking into consideration the direct effect of
menopause on FPG levels are therefore important for the prevention and
treatment of diabetes in postmenopausal women."
The Ministry of Education, Science, Sports, and Culture of Japan
supported this study. The authors have disclosed no relevant financial
relationships
Clinical Context
According to the authors of the current study, FPG is an important
measure of prediabetes, increased FPG levels predict future diabetes
risk, and the risk for diabetes increases with age and is different for
men and women. In women, the prevalence of abnormal glucose metabolism
has been shown to increase around 50 years of age, and estrogen and
progestin may play a role in this as well as the risk for hypertension
and abnormal lipid metabolism.
This is a cross-sectional study from Japan of premenopausal and
postmenopausal women without diabetes presenting to a single center. The
women were screened for FPG to determine the prevalence of glucose
intolerance or impaired FPG and to determine if prevalence of impaired
FPG was higher after menopause.
Study Highlights
- Included were 505 healthy nondiabetic women presenting for
health examination visits to 1 hospital who received a 75-g glucose
tolerance test.
- Diabetes mellitus was defined according to the American Diabetic
Association criteria.
- Menopause was defined as 6 or more consecutive months of
amenorrhea not caused by surgery or other obvious causes.
- Excluded were women younger than 41 years or older than 60 years
and those with diabetes, history of hysterectomy, malignant disease,
thyroid disease, inflammatory bowel disease, and serious medical
conditions.
- Blood was collected for biochemistry after 12 hours of fasting
and the homeostasis model assessment insulin sensitivity index and
pancreatic β-cell function index were calculated from FPG and
insulin levels.
- Anthropometric measurements were made and blood pressure taken.
- Mean age was 52.2 years, average BMI was 22.8 kg/m², mean
triglyceride level was 84 mg/dL, total cholesterol level was 214 mg/dL,
and LDL cholesterol level was 130 mg/dL.
- Mean systolic blood pressure was 108 mm Hg and diastolic blood
pressure was 68 mm Hg.
- 208 women were premenopausal and 297 were postmenopausal.
- Age, BMI, triglyceride level, total cholesterol level, LDL
cholesterol level, blood pressure, and homeostasis model assessment
sensitivity index rose across quintiles of FPG levels, but HDL
cholesterol and homeostasis model assessment pancreatic β-cell
function index did not.
- Univariate regression analysis was performed for FPG and the
variables examined.
- Among the variables examined, age, BMI, triglycerides, total
cholesterol level, systolic and diastolic blood pressure, and
menopause status were significantly and positively correlated with
FPG levels.
- HDL cholesterol was not correlated with FPG levels.
- Of the variables studied, only BMI, menopause status, and
triglycerides were independently associated with FPG levels.
- Age and LDL cholesterol levels were not independently associated
with increased FPG levels.
- FPG levels were significantly higher in postmenopausal women in
the 47- to 55-year age group (mean FPG level, 96.8 mg/dL; n = 154)
vs those in women of the same age who were premenopausal (mean FPG
level, 93.9 mg/dL; n = 125; P = .0012).
- The authors concluded that menopause per se, rather than older
age, was the determinant of FPG levels in women.
- The authors suggested that this finding reinforces the sex
differences in diabetes prevalence.
Pearls for Practice
- Age, BMI, triglyceride level, LDL cholesterol level, and
menopause status are associated with increasing FPG levels in
nondiabetic premenopausal and postmenopausal women, but HDL
cholesterol level is not.
- Menopause status, rather than age, is an independent predictor
of higher FPG levels in nondiabetic women, as are BMI and
triglyceride levels.
