Osteoporosis, Fractures and MetS in Postmenopausal Women
Osteoporosis, Fractures and MetS in Postmenopausal Women
A total of 270 caucasian postmenopausal women (age range: 50–90 yr) living in the Rabat area participated in the present study. Women were recruited through advertisements and "word of mouth" from june 2012 to march 2013. Original inclusion criteria were age > 50, menopause > 1 year and no previous osteoporotic fracture or known diagnosis of osteoporosis. Women with liver or renal disease, endocrine or metabolic abnormalities, and receiving medicine known to influence bone mineralization, such as corticosteroids, heparin, anticonvulsants, vitamin D, bisphosphonates, were excluded. Our institutional review board (Comité d'éthique et de recherche de l'hôpital Militaire Mohammed V) approved this study. The procedures of the study were in accordance with the Declaration of Helsinki, and local ethics committee approval was obtained for the study (Comité d'éthique de la Faculté de Médecine et de Pharmacie de Rabat). All the participants gave an informed and written consent. Each subject completed a standardized questionnaire designed to document putative risk factors of osteoporosis. The questionnaire collected information on current medication use, history of peripheral traumatic fractures, smoking habits, and level of physical activity in leisure time, along with calcium consumption and the use of vitamins and medications. Height and weight were measured in light indoor clothes without shoes. Body mass index (BMI)] was calculated by dividing weight in kilograms by height in meters squared. Waist was measured in centimeters at the bending point using a flexible tape measure, with the participant wearing single-thickness clothing and standing in an erect position with feet together. Although this is not a population-based cohort, care was taken to ensure representativeness of the general population with a particular regard to the inclusion of a wide range of age categories, body sizes and activities. We did not exclude individuals using inhalation steroids or with certain lifestyle habits such as heavy smoking, being sedentary, being athletic, or having a high or low calcium intake, which are examples of voluntary factors that may have some impact on bone metabolism.
The women were asked whether they usually drank milk or alcohol; if they ate cheese or yogurt; if they did gymnastics or jogging/walking and if they smoked tobacco. If the answer was positive, they were asked to quantify their average current consumption (evaluated on the 7 day prior to the interview) of milk or yogurt (mL/day), cheese (g/day) and wine and/or spirits (mL/day). Tobacco smoking was quantified as average number of cigarettes (smoked/day) multiplied by the number of years of smoking, gymnastics as min/week, or jogging/walking as min/day. Finally, patients were categorized as never smokers, ex-smokers and current smokers; high, normal and low calcium intake (more than 1500 mg/day, between 800 and 1500 day − 1 and below 800 mg/day, respectively); high, moderate and low physical activity (more than 3, 2–3 and below 1 hour/week, respectively).
BMD was determined by a Lunar Prodigy Vision DXA system (Lunar Corp., Madison, WI). The DXA scans were obtained by standard procedures supplied by the manufacturer for scanning and analysis. All BMD measurements were carried out by 2 experienced technicians. Daily quality control was carried out by measurement of a Lunar phantom. At the time of the study, phantom measurements showed stable results. The phantom precision expressed as the coefficient of variation was 0.08%. Moreover, reproducibility has been assessed in clinical practice and showed a smallest detectable difference of 0.04 g/cm(spine) and 0.02 (hips). Patient BMD was measured at the lumbar spine (anteroposterior projection at L1-L4) and at the femurs (i.e., femoral neck, trochanter, and total hip). Using the Moroccan female normative data, the World Health Organization (WHO) classification system was applied, defining osteoporosis as T-score ≤ −2.5 and osteopenia as −2.5 < T-score < −1. Study participants were categorized by the lowest T-score of the L1–4 lumbar spine, femur neck, or total femur.
VFs was classified using a combination of Genant semiquantitative (SQ) approach and morphometry in the following manner: each VFA image was inspected visually by two trained clinicians (IG and AM) to decide whether it contained a fracture in any of the visualized vertebrae and assigned by consensus a grade based on Genant SQ scale, where grade 1 (mild) fracture is a reduction in vertebral height of 20–25%, grade 2 (moderate) a reduction of 26–40%, and grade 3 (severe) a reduction of over 40%. In case of doubt regarding fracture grade, the vertebrae in question was measured using built-in morphometry. Automatic vertebral recognition by the software was used. Positioning of the six morphometry points was modified by one of the two clinicians only when the software failed to correctly recognize vertebral heights. The intra-rater reproducibility of this method was evaluated using the kappa score to 0.90 (p < 0.0001). Subjects with no fractures were included in the non-fracture group, whereas those with grade 1 or higher fractures were included in the fracture group. However, as many studies rarely report mild deformities as "fractures", and to realize comparisons with the literature, we distinguished the group of women with grade 1 fractures from the grade 2/3 fracture group. The spinal deformity index (SDI), as described by Kerkeni et al., was then calculated by summing in each patient the grade of each vertebra from T4 to L4. In theory, the SDI value can vary between 0 (no fracture) and 39 (all the assessed vertebrae are grade 3).
The prevalence of MS and its components were defined by NCEP-ATP III criteria. Participants were classified as having the MS if any three of the following were present: abdominal obesity (waist circumference greater than 88 cm), triglycerides of 150 mg/dL (1.7 mmol/L) or greater, HDL cholesterol levels less than 50 mg/dL (1.29 mmol/L), fasting glucose of 110 mg/dL (6.1 mmol/L) or greater, or blood pressure of 130/85 mmHg or greater. Participants with documented use of antihypertensive medication were categorized as meeting the blood pressure criteria. Diabetes was defined by the American Diabetes Association 1998 guidelines (fasting plasma glucose equal or greater than 126 mg/dL or 2-h plasma glucose in 75 g oral glucose tolerance test equal or greater than 200 mg/dL).
Results are presented as means (SD) for continuous variables and as frequencies for categorical variables. To compare patients with and without MS and patients with or without osteoporosis, chi-square test and Student t-test were used. To compare patients with and without VFs, chi-square test and analysis of variance ANOVA were used. Potential risk factors for osteoporosis were finally entered to a stepwise conditional binary logistic regression analysis and the resulted odds ratios with 95% confidence intervals were reported. The level for significance was taken as p ≤ 0.05. Excel 2010 and SPSS 20.0 were used for statistical analysis.
Methods
Subjects
A total of 270 caucasian postmenopausal women (age range: 50–90 yr) living in the Rabat area participated in the present study. Women were recruited through advertisements and "word of mouth" from june 2012 to march 2013. Original inclusion criteria were age > 50, menopause > 1 year and no previous osteoporotic fracture or known diagnosis of osteoporosis. Women with liver or renal disease, endocrine or metabolic abnormalities, and receiving medicine known to influence bone mineralization, such as corticosteroids, heparin, anticonvulsants, vitamin D, bisphosphonates, were excluded. Our institutional review board (Comité d'éthique et de recherche de l'hôpital Militaire Mohammed V) approved this study. The procedures of the study were in accordance with the Declaration of Helsinki, and local ethics committee approval was obtained for the study (Comité d'éthique de la Faculté de Médecine et de Pharmacie de Rabat). All the participants gave an informed and written consent. Each subject completed a standardized questionnaire designed to document putative risk factors of osteoporosis. The questionnaire collected information on current medication use, history of peripheral traumatic fractures, smoking habits, and level of physical activity in leisure time, along with calcium consumption and the use of vitamins and medications. Height and weight were measured in light indoor clothes without shoes. Body mass index (BMI)] was calculated by dividing weight in kilograms by height in meters squared. Waist was measured in centimeters at the bending point using a flexible tape measure, with the participant wearing single-thickness clothing and standing in an erect position with feet together. Although this is not a population-based cohort, care was taken to ensure representativeness of the general population with a particular regard to the inclusion of a wide range of age categories, body sizes and activities. We did not exclude individuals using inhalation steroids or with certain lifestyle habits such as heavy smoking, being sedentary, being athletic, or having a high or low calcium intake, which are examples of voluntary factors that may have some impact on bone metabolism.
The women were asked whether they usually drank milk or alcohol; if they ate cheese or yogurt; if they did gymnastics or jogging/walking and if they smoked tobacco. If the answer was positive, they were asked to quantify their average current consumption (evaluated on the 7 day prior to the interview) of milk or yogurt (mL/day), cheese (g/day) and wine and/or spirits (mL/day). Tobacco smoking was quantified as average number of cigarettes (smoked/day) multiplied by the number of years of smoking, gymnastics as min/week, or jogging/walking as min/day. Finally, patients were categorized as never smokers, ex-smokers and current smokers; high, normal and low calcium intake (more than 1500 mg/day, between 800 and 1500 day − 1 and below 800 mg/day, respectively); high, moderate and low physical activity (more than 3, 2–3 and below 1 hour/week, respectively).
Bone Mineral Density (BMD) Measurement
BMD was determined by a Lunar Prodigy Vision DXA system (Lunar Corp., Madison, WI). The DXA scans were obtained by standard procedures supplied by the manufacturer for scanning and analysis. All BMD measurements were carried out by 2 experienced technicians. Daily quality control was carried out by measurement of a Lunar phantom. At the time of the study, phantom measurements showed stable results. The phantom precision expressed as the coefficient of variation was 0.08%. Moreover, reproducibility has been assessed in clinical practice and showed a smallest detectable difference of 0.04 g/cm(spine) and 0.02 (hips). Patient BMD was measured at the lumbar spine (anteroposterior projection at L1-L4) and at the femurs (i.e., femoral neck, trochanter, and total hip). Using the Moroccan female normative data, the World Health Organization (WHO) classification system was applied, defining osteoporosis as T-score ≤ −2.5 and osteopenia as −2.5 < T-score < −1. Study participants were categorized by the lowest T-score of the L1–4 lumbar spine, femur neck, or total femur.
Vertebral Fracture Assessment
VFs was classified using a combination of Genant semiquantitative (SQ) approach and morphometry in the following manner: each VFA image was inspected visually by two trained clinicians (IG and AM) to decide whether it contained a fracture in any of the visualized vertebrae and assigned by consensus a grade based on Genant SQ scale, where grade 1 (mild) fracture is a reduction in vertebral height of 20–25%, grade 2 (moderate) a reduction of 26–40%, and grade 3 (severe) a reduction of over 40%. In case of doubt regarding fracture grade, the vertebrae in question was measured using built-in morphometry. Automatic vertebral recognition by the software was used. Positioning of the six morphometry points was modified by one of the two clinicians only when the software failed to correctly recognize vertebral heights. The intra-rater reproducibility of this method was evaluated using the kappa score to 0.90 (p < 0.0001). Subjects with no fractures were included in the non-fracture group, whereas those with grade 1 or higher fractures were included in the fracture group. However, as many studies rarely report mild deformities as "fractures", and to realize comparisons with the literature, we distinguished the group of women with grade 1 fractures from the grade 2/3 fracture group. The spinal deformity index (SDI), as described by Kerkeni et al., was then calculated by summing in each patient the grade of each vertebra from T4 to L4. In theory, the SDI value can vary between 0 (no fracture) and 39 (all the assessed vertebrae are grade 3).
Metabolic Syndrome
The prevalence of MS and its components were defined by NCEP-ATP III criteria. Participants were classified as having the MS if any three of the following were present: abdominal obesity (waist circumference greater than 88 cm), triglycerides of 150 mg/dL (1.7 mmol/L) or greater, HDL cholesterol levels less than 50 mg/dL (1.29 mmol/L), fasting glucose of 110 mg/dL (6.1 mmol/L) or greater, or blood pressure of 130/85 mmHg or greater. Participants with documented use of antihypertensive medication were categorized as meeting the blood pressure criteria. Diabetes was defined by the American Diabetes Association 1998 guidelines (fasting plasma glucose equal or greater than 126 mg/dL or 2-h plasma glucose in 75 g oral glucose tolerance test equal or greater than 200 mg/dL).
Statistical Analysis
Results are presented as means (SD) for continuous variables and as frequencies for categorical variables. To compare patients with and without MS and patients with or without osteoporosis, chi-square test and Student t-test were used. To compare patients with and without VFs, chi-square test and analysis of variance ANOVA were used. Potential risk factors for osteoporosis were finally entered to a stepwise conditional binary logistic regression analysis and the resulted odds ratios with 95% confidence intervals were reported. The level for significance was taken as p ≤ 0.05. Excel 2010 and SPSS 20.0 were used for statistical analysis.
Source...