Background: Collagen hydrolysate is a nutritional supplement that has been shown to exert an anabolic effect on cartilage tissue. Its administration appears beneficial in patients with osteoarthritis.Objective: To investigate the effect of collagen hydrolysate on activity-related joint pain in athletes who are physically active and have no evidence of joint disease.Design and setting: A prospective, randomized, place bo-controlled, double-blind study was conducted at Penn State University in University Park, Pennsylvania. Parameters including joint pain, mobility, and inflammation were evaluated with the use of a visual analogue scale during a 24-week study phase.Study participants: Between September 2005 and June 2006, 147 subjects who competed on a varsity team or a club sport were recruited. Data from 97 of 147 subjects could be statistically evaluated.Intervention: One hundred and forty-seven subjects (72 male, 75 female) were randomly assigned to two groups: a group (n = 73) receiving 25 mL of a liquid formulation that contained 10 g of collagen hydrolysate (CH-Alpha)* and a group (n = 74) receiving a placebo, which consisted of 25 mL of liquid that contained xanthan.Main outcome measures: The primary efficacy parameter was the change in the visual analogue scales from baseline during the study phase in relation to the parameters referring to pain, mobility, and inflammation.Results: When data from all subjects (n 97) were evaluated, six parameters showed statistically significant changes with the dietary supplement collagen hydrolysate (CH) compared with placebo: joint pain at rest, assessed by the physician (CH vs. placebo (-1.37 +/- 1.78 vs. -0.90 +/- 1.74 (p = 0.025)) and five parameters assessed by study participants: joint pain when walking (-1.11 +/- 1.98 vs. -0.46 +/- 1.63, p = 0.007), joint Pain when standing (-0.97 +/- 1.92 vs. -0.43 +/- 1.74, p = 0.011), joint pain at rest (-0.81 +/- 1.77 vs. -0.39 +/- 1.56, p 0.039), joint pain when carrying objects (-1.45 +/- 2.11 vs. -0.83 +/- 1.71, p = 0.014) and joint pain when lifting (-1.79 +/- 2.11 vs. -1.26 +/- 2.09, p = 0.018). When a subgroup analysis of subjects with knee arthralgia (n = 63) was performed, the difference between the effect of collagen hydrolysate vs. placebo was more pronounced. The parameter joint pain at rest, assessed by the physician, had a statistical significance level of p = 0.001 (-1.67 +/- 1.89 vs. -0.86 +/- 1.77), while the other five parameters based on the participants' assessments were also statistically significant: joint pain when walking (p = 0.003 (-1.38 +/- 2.12 vs. -0.54 +/- 1.65)), joint pain when standing (p = 0.015 (-1.17 +/- 2.06 vs. -0.50 +/- 1.68)), joint pain at rest with (p = 0.021 (-1.01 +/- 1.92 vs. -0.47 +/- 1.63)), joint pain when running a straight line (p 0.027 (-1.50 +/- 1.97 vs. -0.80 +/- 1.66)) and joint pain when changing direction (p = 0.026 (-1.87 +/- 2.18 vs. -1.20 +/- 2.10)).Conclusion: This was the first clinical trial of 24-weeks duration to show improvement of joint pain in athletes who were treated with the dietary supplement collagen hydrolysate. The results of this study have implications for the use of collagen hydrolysate to support joint health and possibly reduce the risk of joint deterioration in a high-risk group. Despite the study's size and limitations, the results suggest that athletes consuming collagen hydrolysate can reduce parameters (such as pain) that have a negative impact on athletic performance. Future studies are needed to support these findings.

PURPOSE: Although energy deficiency is known to disrupt reproductive function in exercising women, no studies have examined whether the susceptibility to menstrual disturbances is altered with increased age. Therefore, the purpose of this study was to determine whether increased age is associated with reduced susceptibility to menstrual disturbances caused by chronic energy deficiency. METHODS: A subset of twenty-four premenopausal women (12 young and 12 middle aged) from a larger study were matched according to the amount weight lost during a three month diet and exercise intervention. Menstrual status was assessed with daily urine samples and measurement of estrogen (E1 G) and progesterone (PdG) conjugates using ELISA. The occurrence of menstrual disturbances, i.e., short luteal phases, inadequate luteal phases, oligomenorrheic cycles, and anovulatory cycles was quantified according to the number of defects/number of cycles observed. Independent samples t-tests were conducted to determine if there was a significant difference between younger and older women in the occurrence of menstrual disturbances. RESULTS: The results are shown below:TableCONCLUSIONS: Older age was associated with significantly fewer disturbances in response to weight loss resulting from a diet and exercise intervention. These results suggest that factor(s) associated with increased age confer protection against menstrual disturbances caused by energy deficiency.

0531 Leptin is strongly associated with body composition parameters, and some studies show significant associations with energy expenditure. Few prospective diet and exercise studies have determined whether changes in leptin parallel indices of body composition, changes in dietary intake, or changes in energy expenditure. PURPOSE: Because leptin is a key metabolic signal involved in energy homeostasis and reproductive function, the association between changes in leptin and changes in other metabolic parameters was examined in a large prospective study on exercise on the menstrual cycle. METHODS: 53 sedentary, normal weight, college age women were randomly assigned to control or exercise groups for a three month controlled feeding and exercise study. Screening confirmed ovulatory status and absence of factors that impact reproductive or metabolic status. A control cycle and then 3 cycles where exercise and feeding occurred were monitored. Aerobic exercise and diet were prescribed as kcals of a % of eucaloric intake. Groups were “clamped” at 5 levels of energy balance. Controls remained eucaloric and did no exercise. Three of four exercise groups were in energy deficits ranging from−15 % to – 60 % of eucaloric intake and in one food was increased to achieve energy balance (0%). Training was 5 × per wk. Serial measurements of body weight (2 × per week), body composition, metabolic hormones, energy expenditure components, VO2max, stress, and reproductive hormones were performed. RESULTS: Leptin correlated at baseline (n = 53; p<0.05 for all) with age (r = −.33), age of menarche (r = −.31), % fat (r = .611), weight (r = .50), fat mass (r = .63), and BMI (r = .49), but not eucaloric intake (kcals), resting metabolic rate (kcal/min), physical activity energy expenditure (kcals), or RQ (p > 0.05 for all). In the 41 subjects that completed the study, leptin, body weight, and fat mass, and body weight declined significantly (Leptin = 10.0 ± 4.8 to 8.0 ± 4.0 ng/ml; p < 0.05; ANOVA); significant correlations between the change in leptin and the changes in other parameters were BMI (r = .48; p<0.002), weight (r = .50; p < 0.002) and fat mass (r = .33; p <0.04). No significant relationships existed between baseline leptin, changes in leptin, and baseline or changes in energy expenditure parameters. CONCLUSION: Decreases in leptin after a diet and exercise intervention closely parallel changes in body composition but not energy expenditure or food intake. Modulation of chronic leptin levels is driven by energy stores; a role for leptin in modulation of energy expenditure is not supported. Supported by NIH RO1 AR3945–01 and MO1 RR 10732.