To determine bone mineral density, rate of osteoporosis in overweight and obesity subjects. Subjects and method: A cross-sectional study on 341 cases with BMI ≥ 23 compared with control group of 129 people with 18 ≤ BMI < 23.
Journal of military pharmaco-medicine no9-2019 ASSESSMENT OF BONE MINERAL DENSITY, OSTEOPOROSIS RATE IN THE SUBJECTS OF OVERWEIGHT AND OBESITY Dao Quoc Viet1; Nguyen Tien Binh2; Nguyen Thi Phi Nga3 SUMMARY Objectives: To determine bone mineral density, rate of osteoporosis in overweight and obesity subjects Subjects and method: A cross-sectional study on 341 cases with BMI ≥ 23 compared with control group of 129 people with 18 ≤ BMI < 23 Result: - The average of bone mineral density of femoral neck (total, neck) and lumbar spine bone in 2 the study group (0.97 ± 0.15 g/cm ; 0.91 ± 0.15 g/cm and 1.15 ± 0.22 g/cm respectively) 2 was higher than the control group (0.88 ± 0.13 g/cm ; 0.83 ± 0.12 g/cm and 1.06 ± 0.18 g/cm ) - The ratio of reduction of bone mineral density, osteoporosis of the femoral neck (total, neck) and lumbar spine bone in the study group (12.3%; 25.5% and 31.7%) was lower than control group (27.9%; 45.7% and 48.8%) - Average Z-score of femoral neck (total, neck) and lumbar spine bone in the study group (0.94 ± 0.99; 0.72 ± 0.96 and 0.46 ± 1.32) was higher than the control group (0.39 ± 1.0; 0.27 ± 0.91 and 0.03 ± 1.33) - The average Z-score at the femoral neck (total, neck) position in the normal bone mineral density person of the study group (1.19 ± 0.78; 1.11 ± 0.75) was higher than the control group (0.81 ± 0.82; 0.83 ± 0.75) - The ratio of reduction of bone mineral density and osteoporosis of the femoral neck (total, neck) and lumbar spine in the group with BMI 23 - 24.9 (21.5%; 41.9% and 45.2%) was higher than the group with BMI ≥ 25 (8.9%; 19.4% and 26.6%) Conclusion: In overweight and obesity people, bone mineral density was higher while the ratio of osteoporosis was lower than that of people with normal BMI * Keywords: Bone mineral density; Osteoporosis; Overweight INTRODUCTION Obesity and osteoporosis are two diseases with complicated pathogenesis mechanisms but there are many common points in the mechanism Both diseases are closely related because mesenchymal stromal cells are common precursors for both osteoblasts and adipocytes The aging process can change the composition of bone marrow with increasing fat cells, increase osteoclast activity, and reduce activity of cell produce bone, leading to osteoporosis [2] It was estimated that more than 600 million adults are obesity and more than 200 million people worldwide are osteoporosis [3] Hoabinh Cadre Health Care and Protection Department Vietnam Military Medical University 103 Military Hospital Corresponding author: Dao Quoc Viet (doctorviet1979@gmail.com) Date received: 13/08/2019 Date accepted: 18/11/2019 228 Journal of military pharmaco-medicine no9-2019 Research on the relationship between bone mineral density (BMD) and overweight and obesity has attracted the attention of scientists, but the results of these studies are still different [1, 4] The amount of fat in the body is one of the most important indicators of obesity, and there was much evidence that fat mass can have beneficial effects on bone On the other hand, some studies showed that excessive fat cannot protect to against osteoporosis or fracture by osteoporosis [6] The difference in research design, sample structure, and even the selection of variables can lead to inconsistent or conflicting results Despite the lack of a clear consensus on the effect of fat on bone, several mechanical explanations have been proposed to assist explain the observed phenomena of the relationship between fat and bone Overweight, obesity and osteoporosis are related to each other [7] So far, there have been many studies on BMD on different pathological subjects, but most of these studies, the relationship between BMD - BMI is only a secondary observation variable, not the main goal in the studies in overweight and obese subjects Therefore, we carried out the article Assessment of BMD, rate of osteoporosis in overweight and obesity people SUBJECTS AND METHODS Subjects The study was conducted on 470 subjects, including groups: - Study group: 341 subjects under the management of the Department of Health Protection and Care of Hoabinh province, determined to be overweight and obese according to WHO standards through periodic health examination at the clinic and management healthy of officials in Hoabinh province - Control group: 129 subjects under the management of the Department of Health Protection and Care of Hoabinh province, determined to have a body weight within normal limits according to WHO standards by periodic health examination in the clinic and management healthy of officials in Hoabinh province Time to conduct research from 2015 to 2019 * Standard for research group selection: - BMI ≥ 23 - Age: ≥ 40 - Agreed to participate in the study * Standard for control group selection: - People with BMI within normal limits (18 < BMI < 23) - Age: ≥ 40 - Agreed to participate in the study * Exclusion criteria for both groups: - Cases of treatment for hormone replacement - Women had removed the ovary - History and current use of prolonged corticosteroids - Subjects with acute internal medical problems - There were diseases such as bone metastatic cancer, chronic kidney disease, hepatobiliary disease - digestion, thyroid disease, parathyroid gland, diabetes, or are using drugs and medicinal products that affect bone metabolism 229 Journal of military pharmaco-medicine no9-2019 - Subjects did not agree to participate in the study Methods Prospective research, cross-sectional description, comparison control Applying the formula for calculating sample size, calculating the ratio in descriptive research: Zα/2 x p (1-p) n= d2 With Zα/2 = 1.96 (level of confidence 95%); d: Tolerated margin of error, we chosen d = 0.05; p: Estimated proportion of osteoporosis Select p = 0.84 [8] Changing the number into the formula, calculating n (minimum) was 207 cases - Measure BMD by DEXA method (DEXXUM T machine Osteosys, Korea) at Clinic and Health Management of Hoabinh province + Neck of the femur: Measuring the neck area of the femur (neck), the large transfer area (troch), the interlocking area (inter), the triangle Ward (Ward’s) according to WHO's recommendations Results of measuring bone mineral density of femur are determined by methods: Arithmetic mean of the measured area indexes (total) Values measure the neck area of the neck (neck) BMD displays by T-score and Z-score In fact, through the periodical health examination in 2017, we had selected 341 eligible cases to be included in the research group + Lumbar spine: Measured from area L1 to L4 The result was calculated by the arithmetic mean of the measurement area indicators BMD displays by T-score and Z-score During this time, we had selected 129 eligible cases included in the control group - Data processing method: Data processing by software SPSS 20.0 RESULTS Table 1: Average of BMD of study group and control group Characteristics Study group (n = 341) Control group (n = 129) p BMD (total) 0.97 ± 0.15 0.88 ± 0.13 < 0.001 BMD (neck) 0.91 ± 0.15 0.83 ± 0.12 < 0.001 BMD L1 1.09 ± 0.21 1.00 ± 0.16 < 0.001 BMD L2 1.14 ± 0.21 1.04 ± 0.18 < 0.001 BMD L3 1.18 ± 0.23 1.09 ± 0.22 < 0.001 BMD L4 1.20 ± 0.24 1.09 ± 0.24 < 0.001 BMD L1-L4 1.15 ± 0.22 1.06 ± 0.18 < 0.001 Femoral neck Lumbar spine Average of BMD femoral neck and lumbar spine in study group was higher than control group (p < 0.001) 230 Journal of military pharmaco-medicine no9-2019 Table 2: Ratio reduced BMD, osteoporosis Study group Femoral neck Neck Lumbar spine Control group (n = 129) Numbers Percentage Numbers Percentage Normal 299 87.7 93 72.1 Reduce BMD, osteoporosis 42 12.3 36 27.9 Normal 254 74.5 70 54.3 Reduce BMD, osteoporosis 87 25.5 59 45.7 Normal 233 63.3 66 51.2 Reduce BMD, osteoporosis 108 31.7 63 48.8 Ratio of osteoporosis Total Study group (n = 341) p < 0.001 < 0.001 < 0.05 Ratio of reduced BMD, osteoporosis in study group was lower than control group at both areas (femoral neck and lumbar spine) (p < 0.05) Table 3: Characteristics of Z-score Characteristics Average Z-score Average Z-score in reduced BMD, steoporosis Average Z-score in normal BMD people Study group Control group p Lumbar spine 0.46 ± 1.32 0.03 ± 1.33 < 0.01 Femoral neck (total) 0.94 ± 0.99 0.39 ± 1.0 < 0.001 * Femoral neck (neck) 0.72 ± 0.96 0.27 ± 0.91 < 0.001 * Lumbar spine -0.89 ± 0.69 -0.97 ± 0.92 > 0.05 * Femoral neck (total) -0.7 ± 0.56 -0.68 ± 0.53 > 0.05 * Femoral neck (neck) -0.39 ± 0.5 -0.41 ± 0.54 > 0.05 * Lumbar spine 1.19 ± 0.96 1.02 ± 0.84 > 0.05 Femoral neck (total) 1.19 ± 0.78 0.81 ± 0.82 < 0.001 Femoral neck (neck) 1.11 ± 0.75 0.83 ± 0.75 < 0.01 * * (*: Mann - Whiney test) - Average Z-score in study group was higher than control group (p < 0.05) - Average Z-score in femoral neck in normal BMD & osteoporosis people in study group was higher than control (p < 0.05) Table 4: Some cut points of Z-score Value cut-off Femoral neck Lumbar spine Study group, n (%) Control group, n (%) p Z-score (total) < -1 11 (3.4) (6.2) > 0.05 Z-score (neck) < -1 (2.4) (5.4) > 0.05 Z-score < -1 44 (14.2) 26 (20.5) > 0.05 Z-score (total) < -1.5 17 (5.5) 14 (11) < 0.05 Z-score (total) < -2 (2.3) (4.7) > 0.05 At point of lumbar spine, with cut-off Z-score < -1.5, in overweight and obesity group (5.5%) was lower than control group (11%) (p < 0.05) 231 Journal of military pharmaco-medicine no9-2019 Table 5: Relationship between reduced BMD, osteoporosis with BMI BMI from 23 - 24.9 (n = 93) Characteristics Numbers Percentage 73 78.5 226 91.1 Reduced BMD, osteoporosis 20 21.5 22 8.9 Normal 54 58.1 200 80.6 Reduced BMD, osteoporosis 39 41.9 48 19.4 Normal 51 54.8 182 73.4 Reduced BMD, osteoporosis 42 45.2 66 26.6 Normal Total Femoral neck Neck Lumbar spine BMI ≥ 25 (n = 248) p Numbers Percentage < 0.05 < 0.05 < 0.05 Ratio of reduced BMD and osteoporosis in femoral neck and lumbar spine in overweight group was higher than obesity group (p < 0.05) DISCUSSION Obesity and osteoporosis are two diseases with a complex pathogenesis mechanism with a multifactorial cause, including genetic factors, environmental factors and the possibility of interactions between obesity and osteoporosis It was previously thought that obesity and osteoporosis were two unrelated diseases, but recent studies have shown that both diseases share some common genetic and environmental factors [6] The study results showed that the average value of BMD in the femoral neck (total, neck) and the lumbar spine (in the individual vertebrae from L1-L4 and the mean value of all segments of the vertebrae) in group of overweight & obesity were higher than the normal weight group (p < 0.001) (table 1) When comparing with WHO standard for diagnosis of osteoporosis, the rate of reduction of BMD and osteoporosis in the study group was lower than the control group in both 232 positions of neck of femur and lumbar spine (p < 0.05) (table 2) Besides, when assessing the value of Z-score (table 3), we found: - Average Z-score in the study group was higher than the control group (p < 0.05) - Average Z-score at the femoral neck in the normal BMD of the study group was higher than the control group (p < 0.05) We used statistic ratio of different cutoff values of Z-score for comparison between the two groups and found that at the lumbar spine position, with cut-off Z-score < -1.5 at the overweight and obesity group (5.5%) was lower than the control group (11%) (p < 0.05) (table 4) From the definition of the Z-score, the nature of Z-score reflects the BMD of the study subjects adjusted for age and menopause status in women Therefore, the lower Z-score, the more negative values reflect the subjects with rapid bone turnover, faster and more bone loss than other subjects of the same age and gender Journal of military pharmaco-medicine no9-2019 - The ratio of reduction of BMD and osteoporosis of the femoral neck (total, neck) and lumbar spine in the group with BMI 23 - 24.9 (21.5%; 41.9% and 45.2%) was higher than the group with BMI ≥ 25 (8.9%; 19.4% and 26.6%) with p < 0.05 respectively (table 5) Thus, our research results were consistent with the research of the above authors and supported the hypothesis that obesity had a positive impact on BMD and the rate of osteoporosis The study by Rexhepi S et al (2015) [7] showed that in premenopausal women, there was a difference in the value of BMD osteoporosis between different groups of BMI (p = 0.023) Jiang Y et al (2017) [9] studied 58 Chinese people aged 50 to 89 years and showed that BMD increased in all positions when BMI increased (all p < 0.01) Multivariate regression analysis showed that BMI is a protective factor for BMD The study by Chan MY et al (2014) [10] followed 2,199 women and 1,351 men aged 60 and older In univariate analysis, BMI was associated with reduced risk of fracture in women ([HR 0.92; 95%CI: 0.85 - 0.99) and in men (HR 0.77; 95%CI: 0.67 - 0.88) The explanation for overweight and obesity hypothesis positively affects bones with many points The first point is that when the body weight increases, the load on the bone increases and therefore the bone mass will increase to accommodate the larger load Besides, fat cells are an important source for estrogen production in postmenopausal women, and estrogen is known to inhibit bone resorption of osteoclasts When there was an increase in adipose tissue with an increase in BMI in postmenopausal women, the results increased estrogen production, inhibition of osteoclasts, and increased bone mass results In the EPIC study, early menopausal women with low BMI were found to have nearly 12% lower index of BMD and were twice as likely to lose bone after two years of follow-up when compared with women with a high BMI This indicates that a low BMI is an important risk factor for osteoporosis, which is the underlying cause of decreased bone mass and rapid bone loss [1] Age and sex: Changes in sex hormone levels increase the risk of developing both obesity and osteoporosis In particular, age-related changes, body composition, metabolic factors, and postmenopausal hormonal levels, along with a decline in physical activity, can all be a mechanism for weight gain trend, usually characterized by an increase in fat mass and a reduction in lean mass Many evidences supported close relationships between fat tissue and skeletons [3] The study by Phan Thanh Tra Mi et al (2016) [1] on 397 men in districts in Hochiminh City The results showed that the rate of osteoporosis of men in districts was 23.68% Several factors related to male osteoporosis: High age, low education level, occupation, low BMI, history of fractures, glucocorticoid use, attitude towards osteoporosis prevention However, there were other studies proving that being overweight and obesity negatively affect bone density When analyzing osteoporosis risk by obesity level, Neglia C et al (2016) [5] found that 233 Journal of military pharmaco-medicine no9-2019 the risk of osteoporosis increased with obesity level Similarly, the research results of Kang D.H et al (2015) [3], Ripka W.L et al (2016) [6] noted that BMD decreased with obesity level (p < 0.01) To support this view, the authors suggested that in obese patients, high blood lipid levels had a direct effect on reducing bone bile [6] Thus, the results of domestic and foreign studies showed that obesity and osteoporosis are two diseases with complex pathogenetic mechanisms with causes of multiple factors including genetic factors, environment and ability interaction between obesity and osteoporosis Both diseases were closely related because mesenchymal stromal cells are a common precursor for both osteoblasts and adipocytes The aging process can change the composition of bone marrow with increasing fat cells, increase activity of osteoclast, and reduce activity of osteoblast, leading to osteoporosis [6] CONCLUSION In overweight and obesity people, BMD wss higher while the rate of osteoporosis wss lower than that of people with normal BMI REFERENCES Phan Thanh Trà Mi, Nguyễn Trung Hoà, Nguyễn Văn Tập Các yếu tố liên quan đến tình trạng loãng xương nam giới ≥ 45 tuổi Thành phố Hồ Chí Minh năm 2015 Tạp chí Y học Thành phố Hồ Chí Minh 2016, 20 (1) Cao J.J Effects of obesity on bone metabolism J Orthop Surg Res 2011, 6, p.30 Hernlund E, Svedbom A, Ivergard M et al Osteoporosis in the European Union: 234 Medical management, epidemiology and economic burden A report prepared in collaboration with the International Osteoporosis Foundation (IOF) and the European Federation of Pharmaceutical Industry Associations (EFPIA) Arch Osteoporos 2013, 8, p.136 Kang D.H, Guo L.F, Guo T et al Association of body composition with bone mineral density in northern Chinese men by different criteria for obesity J Endocrinol Invest 2015, 38 (3), pp.323-331 Neglia C, Argentiero A, Chitano G et al Diabetes and obesity as independent risk factors for osteoporosis: Updated results from the ROIS/EMEROS Registry in a population of five thousand post-menopausal women living in a region characterized by heavy environmental pressure J Environ Res Public Health 2016, 13 (11) Ripka W.L, Modesto J.D, Ulbricht L et al Obesity impact evaluated from fat percentage in bone mineral density of male adolescents PLoS One 2016, 11 (9), p e0163470 Rexhepi S, Bahtiri E, Rexhepi M et al Association of body weight and body mass index with bone mineral density in women and men from Kosovo Mater Sociomed 2015, 27 (4), pp.259-262 Salamat M.R, Salamat A.H, Abedi I et al Relationship between weight, body mass index, and bone mineral density in men referred for dual-energy X-ray absorptiometry Scan in Isfahan, Iran J Osteoporos 2013, p Article ID 205963 Jiang Y, Zhang Y, Jin M et al Agedrelated changes in body composition and association between body composition with bone mass density by body mass index in Chinese han men over 50-year-old PLoS One 2017, 10 (6), p e0130400 10 Chan M.Y, Frost S.A, Center J.R et al Relationship between body mass index and fracture risk is mediated by bone mineral density Miner Res 2012, 29 (11), pp.2327-2335 ... we carried out the article Assessment of BMD, rate of osteoporosis in overweight and obesity people SUBJECTS AND METHODS Subjects The study was conducted on 470 subjects, including groups: - Study... examination at the clinic and management healthy of officials in Hoabinh province - Control group: 129 subjects under the management of the Department of Health Protection and Care of Hoabinh... Management of Hoabinh province + Neck of the femur: Measuring the neck area of the femur (neck), the large transfer area (troch), the interlocking area (inter), the triangle Ward (Ward’s) according