Circulating leptin and adiponectin, and breast density
in premenopausal Mexican women: the Mexican Teachers’
Received: 9 February 2017 / Accepted: 21 June 2017 / Published online: 4 July 2017
Ó Springer International Publishing AG 2017
Purpose Leptin and adiponectin are produced by the adi-
pose tissue. Mammographic density (MD) is one of the
strongest predictors of breast cancer (BC) and is highly
inﬂuenced by adiposity. How the interplay between MD,
obesity, and obesity-related biomarkers inﬂuences BC risk,
however, is still unknown, especially in premenopausal
women, where adiposity seems to be protective for BC.
The aim of the present study was to explore the association
between circulating leptin, adiponectin, and their ratio,
with MD in Mexican premenopausal women who are part
of the large Mexican Teachers’ Cohort (MTC).
Methods A subsample of 2,084 women from the MTC
participated in a clinical evaluation. Of them, 574 pre-
menopausal women were randomly selected, from four
MD strata. Serum leptin and adiponectin concentrations
were measured by immunoassays. Multivariate regression
analyses were performed to compare means of MD by
quartiles of adipokines and their ratio.
Results High leptin and leptin/adiponectin ratio levels
were signiﬁcantly associated with lower percentage MD
and higher absolute and non-absolute dense tissue areas.
High adiponectin levels were signiﬁcantly associated with
lower absolute dense and non-dense tissue areas, but not
with percentage MD. After adjustment for BMI, only the
associations between percentage MD and absolute non-
dense tissue area with leptin remained statistically
Conclusions Leptin, adiponectin, and their ratio were
associated with MD; however, only the positive association
with leptin seemed to be independent from overall obesity.
Keywords Leptin Á Adiponectin Á Mammographic
density Á Premenopausal women Á Obesity
Leptin and adiponectin are adipocytokines that are pro-
duced by two different types of adipose tissues, mainly
visceral for adiponectin, and subcutaneous for leptin [1, 2].
Leptin is a polypeptide hormone that controls feeding
behaviors, and also acts as a growth factor and regulator of
cell proliferation . Adiponectin is one of the most
abundant adipocyte-derived proteins with insulin-sensitiz-
ing, antiproliferative, proapoptotic, and anti-estrogenic
properties [4, 5]. While circulating leptin concentrations
increase with increasing adiposity, adiponectin concentra-
tions decrease [6–8]. The ratio of leptin/adiponectin rep-
resents a good marker of insulin resistance and of
abdominal/central compared to overall adiposity .
Recently, several case–control and prospective studies
have explored the association between circulating leptin
and adiponectin levels and breast cancer risk, indicating
that low circulating adiponectin, and high leptin levels are
associated with an increased breast cancer risk [7, 8].
However, most of the studies conducted in premenopausal
women were retrospective case–control studies, while
prospective studies focused mostly on post-menopausal
& M. Lajous
International Agency for Research on Cancer [IARC], Lyon,
Center for Research on Population Health, National Institute
of Public Health, 7
Cerrada Fray Pedro de Gante # 50,
Mexico 14000, Mexico
Department of Epidemiology, Harvard School of Public
Health, Boston, MA, USA
Cancer Causes Control (2017) 28:939–946