Site-specific associations of muscle thickness with bone mineral density in middle-aged and older men and women.

It is unknown whether age-related site-specific muscle loss is associated with areal bone mineral density (aBMD) in older adults. To examine the relationships between aBMD and whole-body muscle thickness distribution, 97 healthy adults (46 women and 51 men) aged 50-78 years volunteered. Total and appendicular lean soft tissue mass, aBMD of the lumbar spine (LS-aBMD) and femoral neck (FN-aBMD) were determined using dual-energy X-ray absorptiometry. Muscle thickness (MT) was measured by ultrasound at nine sites of the body (forearm, upper arm, trunk, upper leg, and lower leg). Relationships of each co-variate with aBMD were tested partialling out the effect of age. aBMD was not correlated with either MT of the trunk or anterior lower leg in either sex. In men, significant and relatively strong correlations were observed between anterior and posterior upper arms, posterior lower leg, and anterior upper leg MT and LS-aBMD or FN-aBMD. In women, significant correlations were observed between anterior and posterior upper legs, posterior lower leg, and anterior upper arm MT and FN-aBMD. LS-aBMD was only correlated with forearm and posterior upper leg MT in women. In conclusion, the site-specific association of MT and aBMD differs between sexes and may be associated with the participants' daily physical activity profile.

Cessation from cigarette smoking: changes in body weight, body composition, resting metabolism, and energy consumption.

This study examined the effect of cessation from smoking on body weight, body fat, resting metabolic rate (RMR), and caloric consumption. Twenty-six women aged 25 to 45 years (mean, 37.2 +/- 4.7) who smoked 20 or more cigarettes per day for the past 5 years served as volunteers. Twelve subjects abstained from smoking for a period of 60 days (EXSMOKERS). Six stopped smoking for 30 days, then resumed the habit for an additional 30 days (RESMOKERS). Eight subjects continued to smoke for the entire 60 days (SMOKERS). Additionally, 10 women who had never smoked served as nonsmoking controls (NONSMOKERS). Body weight was recorded weekly and body fat was calculated from body density as determined by hydrostatic weighing. RMR was assessed by open-circuit spirometry. Caloric intake was obtained from 3-day food records using a computerized nutrient data base. Group means for body weight, body fat, RMR, and caloric intake were compared using a repeated measures ANOVA with a Scheffe post hoc at day 0 (baseline), day 30, and day 60 of cessation from smoking. NONSMOKERS weighed significantly (P less than .05) more, but were no fatter than all smoker groups at day 0. Body weight significantly increased by 1.8 kg (EXSMOKERS) and 2.1 kg (RESMOKERS) at day 30 of cessation. By day 60 EXSMOKERS' body weight had increased an additional 1.8 kg to 61.6 +/- 6.4 kg, while return to smoking (RESMOKERS) resulted in a 3.1 kg loss of body weight to 57.9 +/- 7.9 kg.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation and genotypic comparison of oral streptococci from experimental bitemarks.

The feasibility of recovering and genotypically comparing oral bacteria from bitemarks for forensic purposes was assessed experimentally. Volunteers firmly bit their own upper arms and bitemarks were sampled at intervals to recover viable Streptococcus isolates. The recoverability of bacteria decreased over time but an average of more than one thousand viable organisms was recovered 24 hrs after biting, provided the site remained relatively undisturbed. Physical exertion, manual rubbing and application of moisturizing lotion all decreased bacterial recoverability compared to controls. Streptococci could also be recovered from bites inflicted on various fabrics. Genomic profiles (DNA "fingerprints") of bacteria recovered from bitemarks could be identified exclusively with those from the teeth of the individual responsible. These findings suggest that a bacterial genotyping approach to bitemark analysis could have forensic application in situations where the perpetrator's DNA cannot be recovered from an oral contact site.

Physiological effects of walking and running with hand-held weights.

To study the effect of walking and running with hand-held weights on oxygen uptake (VO2), heart rate (HR), respiratory exchange ratio (RER), and ratings of perceived exertion (RPE), ten males (means age = 26.1 +/- 5.5 yrs) completed 4 submaximal treadmill tests during each of four test sessions, one week apart. Protocols consisted of carrying one of four randomly assigned hand-held weight configurations (0, 0.45, 1.36, 2.27 kg per hand) while walking or running for 5-min at each of four speeds (4.8, 6.4, 8.0, 9.6 km/hr) at 4% grade. Open circuit spirometry methods were utilized for the determination of steady rate VO2 and RER. Heart rate was recorded electrocardiographically throughout the test. Subjects maintained normal arm swing patterns. Carrying hand-held weights did not significantly increase VO2 (ml.kg-1.min-1) at either walking speed (4.8, 6.4 km/hr). At the two running speeds (8.0, 9.6 km/hr) VO2 was significantly greater when the heaviest load (2.27 kg) was compared to the three lighter loads (0, 0.45, 1.36 kg). The results of this study suggest that walking with hand-held weights of 2.27 kg or less while maintaining a normal arm swing is an insufficient stimulus for significantly increasing VO2 or HR. Running with hand-held weights can increase VO2, with 2.27 kg appearing to be the load threshold.