Vietnam is the 15th most populous country in the world. The country’s population is rapidly aging with significant changes in lifestyle and dietary habits. About 28% of women and 16% of men aged 50 and older are having osteoporosis, but most of them are undiagnosed and not treated.
Vietnam is a developing country, with per-capita GDP being around $2600 (2018 figure). Vietnam has a population of ~97 million, making it the 15th largest country in the world . The country’s population is aging: at present the proportion of population aged 60 years and older is 12%, but this is expected to increase to 25% in 2049 . It can be said that Vietnam is a country that is getting old before getting rich .
The disease epidemiology in Vietnam has also changed substantially over the past four decades. In the 1980s, the most common causes of death were predominantly infectious diseases, maternal and child malnutrition. From the 1990s until now, non-communicable diseases (NCDs) collectively accounted for 71% of total burden of disease in Vietnam, including 60% of all-cause deaths (Harper C. Vietnam Noncommunicable Disease Prevention and Control Programme 2002–2010. WHO Report 2011).
Among NCDs, osteoporosis is recognized as a major public health in Vietnam. However, due to lack of infrastructure and resources, the diagnosis of osteoporosis in Vietnam remains a challenge, particularly in countryside. There are 71 Hologic and 20 GE Lunar densitometers in the entire country, but the majority of these densitometers are in major teaching hospitals. In recent years, more and more provincial hospitals have installed DXA machines for the assessment of osteoporosis. However, the lack of reference ranges and standardization among instruments can lead to misdiagnosis in many cases.
Based on the data from the Vietnam Osteoporosis Study, we estimated that approximately 19% of women and 8% of men aged 50 years and older had osteoporosis as indicated by the femoral neck T-score. However, if BMD from the femoral neck and lumbar spine were combined, the prevalence of osteoporosis increased to 28% of women and 16% of men, which are highly comparable with Caucasian populations.
We have developed an OSTA-style model for assessing the risk of osteoporosis for the Vietnamese population . Our model is simply based on age and weight as follows:
P = exp(-2.667 + 0.120 × age — 0.120 × weight) / (1 + exp(-2.667 + 0.120 × age — 0.120×weight))
and for men:
P = exp(1.782 + 0.068×age — 0.160×weight) / (1 + exp(1.782 + 0.068 × age — 0.160×weight)).
We found that if a women with P > 0.19 and a men with P > 0.10 then they can be considered ‘high risk’ and indicated for DXA scan.
Data on fracture incidence in Vietnam are not available. However, based on radiographs of 209 postmenopausal women and using the Genant’s semi-quantitative method, we found that about 23% of women had undiagnosed vertebral fracture. If the incidence of hip fracture in Thailand is applied in Vietnam, we estimated that the number of hip fractures is 9000 men and 24000 women in 2020.
The vast majority of patients with established osteoporosis are treated with alendronate and zoledronic acid. Most patients with a fracture, even a hip fracture, are not treated; however this is slowly changed when doctors are increasingly realizing the impact of osteoporotic fracture on mortality.
In summary, the prevalence of osteoporosis in Vietnam is not much different from that in Caucasian populations. Lack of reference ranges for bone mineral density and under-treatment in patients with an existing fracture are major issues in Vietnam.
Author: Dr. Lan Ho-Pham