Shumei Cheng

Ultrasound velocity and cortical bone characteristics in vivo.

Abstract: Axial transmission of ultrasound along cortical bone may reflect a combination of material and structural properties of long bone cortices. The goal of this study was to determine the association of speed of sound (SOS) with cortical density (CoD), cortical wall thickness (CWT), and total cortical area (CoA). Quantitative ultrasound (QUS) and peripheral quantitative computed tomography (pQCT) were used to measure the above variables in the distal third of radius and the midshaft of tibia in 51 postmenopausal women aged 62 to 71 years. Univariate regression analysis showed that the site-specific CoD accounted for 34% of the variability in the radial SOS and 29% of that in the tibial SOS (p<0.001 both). SOS was only moderately associated with radial CWT (R2= 0.14, p<0.05) and CoA (R2= 0.12, p<0.05), but not with tibial CWT nor CoA. After controlling for CoD, these dimension-related associations disappeared. Stepwise multiple regression analysis showed that CoD was the only significant determinant of radial SOS (adjusted R2= 0.31), whereas for tibia, not only CoD but also the years since menopause were associated with SOS (adjusted R2= 0.41). In conclusion, out of the studied macroscopic cortical variables, CoD (an apparent surrogate for material properties of bone) was the only determinant of SOS measured in vivo at radial and tibial shafts. The key question that still needs to be answered is whether the SOS information obtained from the peripheral long bone cortical shafts can be translated to describe the mechanical competence and quality of clinically pertinent bones (e.g. proximal femur) of a given individual.

Influence of physical activity and maturation status on bone mass and geometry in early pubertal girls1

This study aimed to evaluate the influence of leisure‐time physical activity on the development of bone mass and density in early pubertal girls. Scores of physical activity were obtained from 242 Finnish girls (10–12 years old within Tanner Stages I–II) using a questionnaire. Bone mass and density were assessed using different densitometric techniques. At Tanner Stage I, active girls had significantly higher bone mineral mass (BMC) and areal bone mineral density (aBMD) of the whole body and cortical volumetric BMD and thickness of the tibial shaft compared with sedentary girls (P<0.05). On the other hand, the active girls at Tanner Stage II showed significantly higher values only in BMC and aBMD at the lumbar spine (P=0.017 and P=0.007, respectively). These indicated that girls at Tanner Stage I with higher leisure‐time physical activity level benefited more from physical activity in terms of their bone development than their less active counterparts. Our results provide evidence that the most beneficial time for physical exercise to exhibit its effect on bone development is in the earlier pubertal period for normal school children, but the positive effect on the lumbar spine is also demonstrated in Tanner Stage II.

Women With and Without Metabolic Disorder Differ in Their Gut Microbiota Composition

The aim of this study was to investigate whether overweight/obese women in metabolic disorder group (MDG, n = 27) differ in their gut microbiota composition from overweight/obese women in non‐metabolic disorder group (NMDG, n = 47) and normal weight women group (NWG, n = 11). Gut microbiota was profiled from fecal samples by 16S rRNA fluorescence in situ hybridization and flow cytometry in 85 premenopausal women. Body composition was measured by bioimpedance, and dietary intakes were collected via food diaries. Standard procedures were used to assess plasma glucose, serum insulin, lipids, and inflammatory status. We found that the proportion of bacteria belonging to Eubacterium rectale‐Clostridium coccoides group, indicating efficient energy harvest from nutrients in gut, was higher in MDG compared to NMDG and NWG, while no difference was found between NMDG and NWG. The proportion of Eubacterium rectale‐Clostridium coccoides group correlated positively with weight, BMI, total fat, fat mass percentage (FM%), visceral fat area, and serum triglycerides, and negatively with high‐density lipoprotein (HDL). Our results indicate that certain members of Eubacterium rectale‐Clostridium coccoides group are associated with obesity‐related MDs not obesity per se.

Clinical Performance of a Highly Portable, Scanning Calcaneal Ultrasonometer

Abstract: The aim of this study was to establish a normative database, assess precision, and evaluate the ability to identify women with low bone mass and to discriminate women with fracture from those without for a highly portable, scanning calcaneal ultrasonometer: the QUS-2. Fourteen hundred and one Caucasian women were recruited for the study. Among them were 794 healthy women 25–84 years of age evenly distributed per 10-year period to establish a normative database. Of these, 171 aged 25–34 years were defined as the young normal group for the purpose of T-score determination. Precision was assessed within 1 day (short-term) and over a 16-week period (long-term) in 79 women aged 25–84 years. Five hundred twenty-eight women ranging from 50 to 84 years of age with or without prevalent fractures of the spine, hip or forearm were measured to compare the QUS-2 with bone mineral density (BMD) of the hip and spine. Mean calcaneal broadband ultrasound attenuation (BUA) was constant in healthy women from 25 to 54 years of age and decreased with increasing age thereafter. Short-term precision, with and without repositioning of the heel, and long-term precision yielded comparable results (BUA SDs of 2.1–2.4 dB/MHz, coefficients of variations (CVs) of 2.5–2.9%). Calcaneal BUA was significantly correlated with BMD of the total hip (TH), femoral neck (FN) and lumbar spine (LS) in 698 women (r= 0.6–0.7, all p<0.0001). A similar relationship was observed for LS BMD compared with either TH or FN BMD (r= 0.7, p<0.0001). Prevalence of osteoporosis in our population (WHO criteria) was 20%, 17%, 21%, and 24% for BUA, BMD of the TH, FN and LS, respectively. Age-adjusted values for a 1 SD reduction in calcaneal BUA and TH and FN BMD predicted prevalent fractures of the spine, forearm, and hip with significant (p<0.05) odds ratios of 2.3, 2.0 and 2.1, respectively. Areas under the receiver operating characteristic curves for age-adjusted bone mass values predicting prevalent fracture were 0.62 for BUA, 0.59 for TH BMD, 0.60 for FN BMD, and 0.57 for LS BMD; all statistically equivalent. We conclude that the QUS-2 calcaneal ultrasonometer exhibits reproducible clinical performance that is similar to BMD of the spine and hip in identifying women with low bone mass and discriminating women with fracture from those without.

Lactation is associated with greater maternal bone size and bone strength later in life

SummaryThe association between lactation and bone size and strength was studied in 145 women 16 to 20xa0years after their last parturition. Longer cumulative duration of lactation was associated with larger bone size and strength later in life.IntroductionPregnancy and lactation have no permanent negative effect on maternal bone mineral density but may positively affect bone structure in the long term. We hypothesized that long lactation promotes periosteal bone apposition and hence increasing maternal bone strength.MethodsBody composition, bone area, bone mineral content, and areal bone mineral density of whole body and left proximal femur were assessed using DXA, and cross-sectional area and volumetric bone mineral density of the left tibia shaft were measured by pQCT in 145 women (mean age 48xa0years, range 36–60xa0years) 16 to 20xa0years after their last parturition. Hip (HSI) and tibia strength indexes (TBSI) were calculated. Medical history and lifestyle factors including breastfeeding patterns and durations were collected via a self-administered questionnaire. Weight change during each pregnancy was collected from personal maternity tracking records.ResultsSixteen to 20xa0years after the last parturition, women who had breastfed in total more than 33xa0months in their life, regardless of the number of children, had greater bone strength estimates of the hip (HSIu2009=u20091.92 vs. 1.61) and the tibia (TBSIu2009=u20095,507 vs. 4,705) owing to their greater bone size than mothers who had breastfed less than 12xa0months (pu2009<u20090.05 for all). The differences in bone strength estimates were independent of body height and weight, menopause status, use of hormone replacement therapy, and present leisure time physical activity level.ConclusionBreastfeeding is beneficial to maternal bone strength in the long run.

Serum metabolic profiles in overweight and obese women with and without metabolic syndrome

ObjectiveTo identify serum biomarkers through metabolomics approach that distinguishes physically inactive overweight/obese women with metabolic syndrome from those who are metabolically healthy, independent of body weight and fat mass.MethodsWe applied nuclear magnetic resonance spectroscopy-based profiling of fasting serum samples to examine the metabolic differences between 78 previously physically inactive, body weight and fat mass matched overweight/obese premenopausal women with and without MetS. MetS was defined as the presence of at least three of the following five criteria: waist circumference ≥88xa0cm, serum triacylglycerol ≥1.7xa0mmol/L, and high density lipoprotein cholesterol (HDL-C) <1.30xa0mmol/L, blood pressureu2009≥u2009130/85xa0mmHg and fasting glucose ≥5.6xa0mmol/L). Principal component analysis was used to reduce the large number of correlated variables to fewer uncorrelated factors.ResultsTwo metabolic factors were associated with MetS independent of BMI, fat mass, waist circumference and physical activity/fitness. Factor comprising branched-chain amino acids (BCAA) and aromatic amino acids (AAA) and orosomucoid was associated with all clinical risk factors (pu2009<u20090.01 for all).ConclusionTwo metabolic factors distinguish overweight/obese women with metabolic syndrome from those who are metabolically healthy independent of body weight, fat mass and physical activity/fitness. In particular, factor comprising BCAA, AAA and orosomucoid seems auspicious biomarker determining metabolic health as it was associated with all clinical risk factors. Further research is needed to determine the public health and clinical significance of these results in terms of screening to identify those at greatest cardio-metabolic risk for whom appropriate intervention strategies should be developed.

Food consumption and nutrient intakes with a special focus on milk product consumption in early pubertal girls in Central Finland

OBJECTIVEnTo evaluate the current status of dietary intakes in early pubertal girls with a special focus on milk products.nnnDESIGNnCross-sectional data using 3-day food records.nnnSUBJECTSnEight hundred and sixty girls, aged 10-12 years, at Tanner maturation stage I-III.nnnRESULTSnThe mean consumption of milk products (620 g day(-1)) was similar to that of a Finnish study in the 1980s, while the consumption of non-milk drinks (403 g day(-1)) had increased. Twelve per cent of the girls had a dairy-restricted diet and consumed significantly less milk products than girls with a non-restricted diet (465 vs. 644 g day(-1), P<0.001). Girls with low milk product consumption had the highest non-milk drinks consumption (P<0.001). The mean energy intake was 7.1 MJ day(-1). No major changes were found in the sources of nutrients. The shares of energy for nutrients were close to recommendations except for saturated fat (13.9 vs. 10% of energy) and carbohydrates (51.5 vs. 55-60% of energy). The mean calcium intake (1117 mg day(-1)) was above the recommendation, while the vitamin D intake (3.1 microg day(-1)) of 88% of the girls was below the recommendation.nnnCONCLUSIONSnThe diet quality of early pubertal girls is close to the recommendations and has improved with respect to fat compared with the 1980s. Consumption of milk products is high although the consumption of non-milk drinks has increased. We found a subgroup of girls who compensate their low milk product consumption with a higher consumption of non-milk drinks. Following a dairy-restricted diet is the main reason for low consumption of milk products.

Bone density of the calcaneus and fractures in 75- and 80-year-old men and women

Abstractbone mineral density of the calcaneus in relation to fractures was studied both retrospectively and prospectively among the 75- and 80-year-old men and women resident in the city of Jyväskylä, Finland, in 1989 and 1990, respectively. The bone measurements were performed at the calcaneus by125I-photon absorption. Retrospective fracture (RF) history after age 50 was collected by questionnaire and interview, and reported fractures were checked from medical records. In the retrospective study, in the 75-year-olds a fracture was found in 22% (n=22) of men and in 45% (n=84) of women. The corresponding figures for the 80-year-olds were 16% (n=9) and 35% (n=48). Over half of the fractures were of the wrist/hand or ankle/leg. Prospective fractures (PF) were recorded over periods of 29–34 months. Twenty of the 75-year-olds and 16 of the 80-year-olds sustained a fracture during the follow-up period. In the 75-year-olds, the results showed that both RF and PF women, together with the RF men, had lower bone area density (BMDa) and volume density (BMDv) than the non-fracture (NF) subjects (p=0.001–0.011). In the 80-year-olds, significantly lower BMDa was found in the RF women (p=0.008) and lower BMDv in the PF women (p=0.024) compared with the NF subjects. During the follow-up period there were no fractures in either of the sex or age groups among those with BMDa and BMDv values greater than 1 SD above the mean. When using logistic regression analysis, BMDv alone explained about 60% of overall fracture probability among the women studied.

Prolonged breast-feeding protects mothers from later-life obesity and related cardio-metabolic disorders

OBJECTIVEnTo investigate the long-term effects of duration of postpartum lactation on maternal body composition and risk for cardio-metabolic disorders in later life.nnnDESIGNnRetrospective study. Body composition was measured using dual-energy X-ray absorptiometry and serum glucose, insulin and lipids were analysed using enzymatic photometric methods 16-20 years after the last pregnancy. Medical history and lifestyle factors were collected via a self-administered questionnaire. Detailed information regarding weight change patterns during each pregnancy was obtained from personal maternity tracking records.nnnSETTINGnCity of Jyväskylä and surroundings in Central Finland.nnnSUBJECTSnTwo hundred and twelve women (mean age 48, range 36-60 years).nnnRESULTSnAt 16-20 years after their last pregnancy, women who had breast-fed for less than 6 months had higher total body fat mass and fat mass percentage, particularly in the android region (46·5 (sd 8·2) %) than mothers who had breast-fed for longer than 6 months (39·0 (sd 10·2) %) or for longer than 10 months (38·4 (sd 10·9) %, P < 0·01). These differences were independent of pre-pregnancy weight and BMI, menopausal status, smoking status, level of education, participation in past and present leisure-time physical activity, and current dietary energy intake. Higher body fat mass was also associated with higher fasting serum glucose concentration and insulin resistance, TAG, LDL cholesterol and total cholesterol concentrations, as well as higher systolic and diastolic blood pressure (P < 0·05 for all).nnnCONCLUSIONSnShort duration of breast-feeding may induce weight retention and fat mass accumulation, resulting in increased risk of cardio-metabolic disorders in later life.

Concerted actions of insulin-like growth factor 1, testosterone, and estradiol on peripubertal bone growth: a 7-year longitudinal study.

A better understanding of how bone growth is regulated during peripuberty is important for optimizing the attainment of peak bone mass and for the prevention of osteoporosis in later life. In this report we used hierarchical models to evaluate the associations of insulin‐like growth factor 1 (IGF‐1), estradiol (E2), and testosterone (T) with peripubertal bone growth in a 7‐year longitudinal study. Two‐hundred and fifty‐eight healthy girls were assessed at baseline (mean age 11.2 years) and at 1, 2, 3.5, and 7 years. Serum concentrations of IGF‐1, E2, and T were determined. Musculoskeletal properties in the left lower leg were measured using peripheral quantitative computed tomography (pQCT). Serum levels of IGF‐1, E2, and T increased dramatically before menarche, whereas they decreased, plateaued, or increased at a lower rate, respectively, after menarche. IGF‐1 level was positively associated with periosteal circumference (PC) and total bone mineral content (tBMC) throughout peripuberty but not after adjustment for muscle cross‐sectional area (mCSA). On the other hand, IGF‐1 was associated with tibial length (TL) independently of mCSA before menarche. T was positively associated with TL, PC, tBMC, and cortical volumetric bone mineral density, independent of mCSA, before menarche but not after. E2 was associated with TL positively before menarche but negatively after menarche. These findings suggest that during puberty, circulating IGF‐1 promotes bone periosteal apposition and mass accrual indirectly, probably through stimulating muscle growth, whereas the effects of sex steroids on bone growth differ before and after menarche, presenting a biphasic pattern. Hence the concerted actions of these hormones are essential for optimal bone development in peripuberty.