Epidemiology of Non-Communicable Diseases

This article discusses the epidemiological associations between the postmenopausal stage in females and the increased risk of osteoporosis. It explores the sensitive period model in the life course theory of epidemiology and its implications for disease risk and progression. The article also highlights the importance of bone remodeling, calcium homeostasis, and the role of estrogen in maintaining bone strength. Strategies for osteoporotic prevention among high-risk populations are also discussed.

Running head: EPIDEMIOLOGY OF NON-COMMUNICABLE DISEASES
EPIDEMIOLOGY OF NON-COMMUNICABLE DISEASES
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1EPIDEMIOLOGY OF NON-COMMUNICABLE DISEASES
Question 1
The scholarly article chosen for this paper is the systematic review by Eastell et al.,
(2016), which discusses extensively on the epidemiological associations between the post-
menopausal stage in females the increased risk of osteoporosis – a non-communicable disease.
The life course which is related to this disease and the chosen research is the ‘sensitive period
model’. The sensitive period model in the life course theory of epidemiology implies a time
period in the life of an individual when being exposed to a particular disease exposure exerts the
highest detrimental effect of disease risk, acquisition and progression than alternative time
periods during the life span (Nishi et al., 2015). Hence, taking insights from the review by Eastell
et al., (2016) as well as the sensitive period model, the risk of osteoporosis disease acquisition is
the highest in females belonging to the post-menopausal stage if acquainted with exposures of
fractures, dietary calcium and Vitamin D deficiencies due to prevalence of reduced estrogen
levels characteristic of this time period.
Bone remodeling and calcium homeostasis are positively associated with each other due
to the interlinked functions of osteoids like osteoblasts and osteoclasts. Osteoblasts are
associated with the initiation of bone modeling by mobilizing serum calcium via calcitonin and
parathyroid hormone mechanisms resulting in bone strength maintenance and repair from minor
injuries and fractures (Lafage-Proust et al., 2015). Osteoclasts alternatively are responsible for
the initiation of bone resorption via secretion of digestive enzymes which results in calcium
leakage from the bone for the maintenance of adequate calcium levels. The female hormone play
a characteristic function in maintenance of bone strength by strengthening the function of
osteoblasts and hindering the function of osteoclasts (Siddiqui & Partridge, 2016). However, the

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post menopausal stage is characterized by a drop in estrogen levels resulting in hindered
equilibrium between osteoclastic and osteoblastic activities, increased bone resorption, loss of
bone mineral density and osteoporotic disease progression of bone porosity and bone fragility.
Hence, for this reason, post menopausal women, when exposed to risk factors like fractures or
calcium-vitamin D (minerals essential for bone formation) deficiency increases their
susceptibilities to osteoporosis due to the estrogen loss-induced increased bone resorption and
decreased bone modeling (Xiao et al., 2016).
The review by Eastell (2016), reports that approximately 50% of women belonging to the
age group of 50 years are at an increased risk of fracture acquisition in the hip or vertebrae which
further results in a detrimental loss of quality of life and hindered physiological, psychological
and social wellbeing. Post menopausal women possess an increased disease risk due to estrogen
deficiency resulting in high bone turnover, loss of trabecular bone connectivity and increased
cortical bone porosity and thinness. Strategies of osteoporotic prevention among such high risk
populations must be aimed at mitigating exposure to key risk factors like fractures and nutritional
deficiency which can be performed through administration of falls prevention procedures and
consumption of a diet consisting of 800 – 1000 mg of calcium/day and Vitamin D
supplementation at more than 50nmol/liter.
Question 2
For the purpose or summarizing the basis of evidence which supports the sensitive period
model concerning post menopausal risk and acquisition of osteoporosis, an electronic literature
search strategy was conducted to obtain articles relevant to this disease association. Using
relevant life science based databases such as BioMed, Medline and PubMed, and key word such

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as ‘osteporosis’, ‘post menopausal women’, ‘calcium deficiency’ and ‘falls’, a total of 5 studies
published within the time frame of 2015 – 2019 were selected (McGowan et al., 2016). The
review by Ji and Yu (2015) noted that that the population of post menopausal women were
highly susceptible to osteoporosis due to estrogen reduction and can be mitigated by dietary and
hormonal therapies. Black, Clifford and Rosen (2016) reviewed that non-medicinal treatments of
falls prevention, exercise administration and calcium supplementation may be helpful in
reducing effects of osteoporotic risk factors of fractures and calcium deficiencies among post
menopausal women. Similarly, the literature review by Cano et al., (2017) examined that the
consumption of 700 to 1200 mg of dietary calcium is beneficial for the management of exposure
towards osteoporotic risk factors like calcium deficiency in post menopausal women. Further, the
review by Baccaro et al., (2015) noted that Brazilian post menopausal women suffering from
osteoporosis must adhere to consumption of an adequate calcium diet and adherence to physical
activity to mitigate harmful effects osteoporosis. Lastly, Cappola and Dolores reviews that post
menopausal women with a high risk of fracture must undergo osteoporosis therapy in the form of
falls prevention strategies, moderate resistance training and diet consumption with adequate
calcium and Vitamin D.
Hence, the above studies indicate a strong evidence base underlying the relationship
between osteoporosis acquisition and post menopausal women when exposed to risks of calcium
deficiency and fractures. All studies were based on the common population group of post
menopausal women and also reported consistent results of increased osteoporosis risk among
post menopausal women when exposed to risk factors. Almost all studies were literature reviews
which are regarded as the highest level of evidence. However, further studies using randomized

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controlled trials are required to assess this association since systematic reviews may be subject to
publication bias and hence incorrect results (Moher et al., 2016).
Question 3
The key methodological limitations in assessing the exposure-outcome relationship can
be attributed to the large availability of studies which are literature reviews. Literature review
results are often subject to publication bias where authors may not consider publishing
conflicting evidence (Fink, 2019). Hence, further research in the form of randomized controlled
trials are required to assess this epidemiological relationship since the same is associated with
reduced possibility of bias (Schulz & Grimes, 2018). While a strong relationship exists between
osteoporosis risk among post menopausal women being exposed to nutritional deficiencies and
fractures during this sensitive life period, confounding variables may exist in the form of
economic factors where such women belonging to high income groups may not show
compliance to this disease model since they are likely to possess greater accessibility,
affordability and education on osteoporosis prevention, nutritious food intake and exercise
adherence (Paschalis et al., 2017). Hence, further high quality evidence and research is required
considering every patient demographic characteristic in order to fully assert this life course
model of osteoporosis epidemiology.

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Black, D. M., & Rosen, C. J. (2016). Postmenopausal osteoporosis. New England Journal of
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