Lifestyle factors affecting heel ultrasound in Greek females across different life stages

Abstract

The use of quantitative ultrasound (QUS) of the bone is rapidly gaining in popularity, and QUS is widely used worldwide for the assessment of skeletal status. Although much has been learned about the influence of various factors on ultrasonic parameters in various populations, similar information at the local level is not available. This study was carried out to examine the effects of anthropometric, dietary, physical activity, reproductive, and other lifestyle factors on QUS parameters in healthy Greek women, including children (n=217), adults (n=235), and elderly (n=369) subjects. Calcaneal QUS measurements were performed with the SAHARA device, which measures broadband ultrasound attenuation (BUA) and speed of sound (SOS) through the os calcis; a composite parameter, the quantitative ultrasound index (QUI), and an estimate of heel bone mineral density (eBMD) were also derived. All QUS indices were higher in adult women than in girls or elderly women (P<0.05). The latter had a similar BUA to girls, but lower SOS, QUI, and eBMD (P<0.05). Most QUS parameters correlated positively with height, weight, body mass index (BMI), hip circumference, organized physical activity, and activity promoting bone mass, but negatively with the time devoted to sedentary activities and absolute carbohydrate intake (P<0.05). Age of menarche and years since menopause were negatively associated with QUS in the adult and elderly women, respectively (P<0.05). The latter relationship, however, was due to the confounding effect of advancing age. Overweight and obese females had significantly higher BUA and eBMD than normal-weight subjects (P<0.05), but similar SOS and QUI; this held true for all age groups. Likewise, in all ages, individuals spending more than 2 h/week on organized activities had significantly higher QUS indices than those spending less time on exercise (P<0.05). Further, postmenarchial girls had significantly higher age-adjusted BUA, SOS, QUI, and eBMD than premenarchial ones (P<0.05). Similarly, all QUS parameters were significantly higher in adult women with an early onset of menarche (<14 years old) than in those with a late onset (P<0.05), but no effects of menarche were detected among the elderly. No significant effects of calcium intake (which was generally adequate), smoking or alcohol drinking (which were generally low) on QUS indices were observed, in either age group. Available independent variables could explain approximately 16%-24% of the total variance in BUA, SOS, QUI and eBMD. The most important positive predictors of QUS were adulthood, time devoted to organized activities, and weight or BMI, while age and carbohydrate intake per se contributed negatively. In conclusion, age, body size, physical activity, and some aspects of reproductive history and diet appear to variably affect calcaneal QUS indices among otherwise healthy Greek women at different life stages.

Quantitative ultrasound in relation to risk factors for low bone mineral density in South African pre-menopausal women

“…In these cases, bone mineral would be directly influenced to a greater extent than would otherwise occur in the normal hormonal environment. In some of the European studies [9], the inverse association with age at menarche was present for all three QUS measures, while other European and Saudi Arabian studies showed associations with BUA but not with SOS and QUI [35, 39]. In Asian Americans [41], no relationship was demonstrated.…”

“…BMI has been found to be consistently associated with bone mineral measurements by DXA [5], but QUS associations with BMI have not been as consistent. Positive associations of BUA and SOS with BMI have been demonstrated in different pre-menopausal populations including European women [9, 12], Arabian women [39], and white and African-American women [13, 38]. However, the multicenter European OPUS study [40], the ESOPO study of Italian women [35], and studies of Turkish women [18] did not find a significant association of QUS measures with BMI.…”

“…We were guided by a previous study of South African black and mixed-race women, where the physical activities shown to be most strongly associated with BMD were walking, walking with loads, and sport activities [29]. The positive effect of current physical activity on BUA and SOS has been demonstrated in South African white women [34] and pre-menopausal European, Asian, and American women [9, 13, 37, 38]. However, for historic physical activity, some researchers have shown a relationship with QUS measures [35, 37] while others have not [34].…”

Longitudinal changes in calcaneal quantitative ultrasound measures during childhood

“…Some studies show increased bone mass in obese children [54, 55], while others report no difference or decreased bone mass (e.g., decreased total body bone mineral apparent density) after adjusting for body size or weight [44, 56, 57]. Similarly, not all studies have reported beneficial effects of obesity on bone changes measured using QUS [53, 57–59]. This may be associated with technical differences among different QUS devices and with whether adjustment for body size or heel width for calcaneal measurement was carried out in these studies.…”

“…Our findings were not significantly changed when we adjusted for heel width or sex-specific stature-forage (i.e., stature z-scores) in our analyses (data not shown). In addition, the effect of body mass appears to be parameter specific [59]. Obese children tend to show advanced growth and maturation possibly resulting in larger bone size and bone mass, compared with normal weight children [54].…”