Creatine Monohydrate Increases Bone Mineral Density in Young Sprague-Dawley Rats

Mass Spectrometry Characterization of the Human Ankle and Hindfoot Fracture Microenvironment in Young and Aged Subjects

Background

Bone regeneration following a fracture is dependent on multiple factors including skeletal stem cells (SSCs). Recruitment, proliferation, and differentiation of the SSCs is guided by the proteins and metabolites found within the fracture microenvironment. Understanding how intrinsic factors affect the fracture microenvironment has been a topic of ongoing investigation. This study sought to determine whether the levels of select proteins and metabolites within the fracture hematoma would be differentially expressed depending on the age of the patient. We hypothesized that a distinct set of proteins and metabolites found within the fracture hematoma microenvironment would be present at varying levels depending on patient age.

Methods

The research study was reviewed and approved by an Institutional Review Board. Hematomas were collected from subjects aged 18 years old or older undergoing surgical intervention for a fracture. Hematoma samples were selected from the biorepository and assigned to one of two fracture groups including young ankle/hindfoot and aged ankle/hindfoot. Protein and metabolite levels within each hematoma were analyzed by liquid chromatography-mass spectrometry.

Results

A total of seven hematomas were included in each the young ankle/hindfoot and aged ankle/hindfoot groups. From the global metabolomic analysis, creatine, 2-methylindoline, and acetyl-L-carnitine were identified as being differentially expressed between both groups. An untargeted metabolomic analysis of the two groups identified significant differences in the levels of an additional 66 metabolites. Proteomic analysis identified 34 proteins that were expressed at significantly different levels.

Conclusions

The level of metabolites and proteins found within the local fracture environment vary by patient age. Future investigations will focus on identifying a role for these proteins and metabolites in bone homeostasis and fracture healing.

Level of Evidence

N/A, basic science investigation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-024-01284-3.

Creatine supplementation for older adults: Focus on sarcopenia, osteoporosis, frailty and Cachexia

Sarcopenia refers to the age-related reduction in strength, muscle mass and functionality which increases the risk for falls, injuries and fractures. Sarcopenia is associated with other age-related conditions such as osteoporosis, frailty and cachexia. Identifying treatments to overcome sarcopenia and associated conditions is important from a global health perspective. There is evidence that creatine monohydrate supplementation, primarily when combined with resistance training, has favorable effects on indices of aging muscle and bone. These musculoskeletal benefits provide some rationale for creatine being a potential intervention for treating frailty and cachexia. The purposes of this narrative review are to update the collective body of research pertaining to the effects of creatine supplementation on indices of aging muscle and bone (including bone turnover markers) and present possible justification and rationale for its utilization in the treatment of frailty and cachexia in older adults.

Current Evidence and Possible Future Applications of Creatine Supplementation for Older Adults

Sarcopenia, defined as age-related reduction in muscle mass, strength, and physical performance, is associated with other age-related health conditions such as osteoporosis, osteosarcopenia, sarcopenic obesity, physical frailty, and cachexia. From a healthy aging perspective, lifestyle interventions that may help overcome characteristics and associated comorbidities of sarcopenia are clinically important. One possible intervention is creatine supplementation (CR). Accumulating research over the past few decades shows that CR, primarily when combined with resistance training (RT), has favourable effects on aging muscle, bone and fat mass, muscle and bone strength, and tasks of physical performance in healthy older adults. However, research is very limited regarding the efficacy of CR in older adults with sarcopenia or osteoporosis and no research exists in older adults with osteosarcopenia, sarcopenic obesity, physical frailty, or cachexia. Therefore, the purpose of this narrative review is (1) to evaluate and summarize current research involving CR, with and without RT, on properties of muscle and bone in older adults and (2) to provide a rationale and justification for future research involving CR in older adults with osteosarcopenia, sarcopenic obesity, physical frailty, or cachexia.

Creatine Supplementation (3 g/d) and Bone Health in Older Women: A 2-Year, Randomized, Placebo-Controlled Trial

BACKGROUND

Creatine supplementation could be a nonexpensive, safe, and effective dietary intervention to counteract bone loss. The aim of this study was to investigate whether long-term creatine supplementation can improve bone health in older, postmenopausal women.

METHODS

A double-blind, placebo-controlled, parallel-group, randomized trial was conducted between November 2011 and December 2017 in Sao Paulo, Brazil. Two hundred postmenopausal women with osteopenia were randomly allocated to receive either creatine monohydrate (3 g/d) or placebo for 2 years. At baseline and after 12 and 24 months, we assessed areal bone mineral density (aBMD; primary outcome), lean and fat mass (through dual X-ray absorptiometry), volumetric BMD and bone microarchitecture parameters, biochemical bone markers, physical function and strength, and the number of falls and fractures. Possible adverse effects were self-reported.

RESULTS

Lumbar spine (p < .001), femoral neck (p < .001), and total femur aBMD (p = .032) decreased across time; however, no interaction effect was observed (all p > .050). Bone markers, microarchitecture parameters, and the number of falls/fractures were not changed with creatine (all p > .050). Lean mass and appendicular skeletal muscle mass increased throughout the intervention (p < .001), with no additive effect of creatine (p = .731 and p = .397, respectively). Creatine did not affect health-related laboratory parameters.

CONCLUSION

Creatine supplementation more than 2 years did not improve bone health in older, postmenopausal women with osteopenia, nor did it affect lean mass or muscle function in this population. This refutes the long-lasting notion that this dietary supplement alone has osteogenic or anabolic properties in the long run.

CLINICAL TRIAL REGISTRY

Clinicaltrials.gov: NCT: 01472393.

Effects of Creatine Supplementation on Properties of Muscle, Bone, and Brain Function in Older Adults: A Narrative Review

Aging is associated with reductions in muscle and bone mass and brain function, which may be counteracted by several lifestyle factors, of which exercise appears to be most beneficial. However, less than 20% of older adults (> 55 years of age) adhere to performing the recommended amount of resistance training (≥ 2 days/week) and less than 12% regularly meet the aerobic exercise guidelines (≥ 150 min/week of moderate to vigorous intensity aerobic exercise) required to achieve significant health benefits. Therefore, from a healthy aging and clinical perspective, it is important to determine whether other lifestyle interventions (independent of exercise) can have beneficial effects on aging muscle quality and quantity, bone strength, and brain function. Creatine, a nitrogen containing organic compound found in all cells of the body, has the potential to have favorable effects on muscle, bone, and brain health (independent of exercise) in older adults. The purpose of this narrative review is to examine and summarize the small body of research investigating the effects of creatine supplementation alone on measures of muscle mass and performance, bone mineral and strength, and indices of brain health in older adults.

Effectiveness of Creatine Supplementation on Aging Muscle and Bone: Focus on Falls Prevention and Inflammation

Sarcopenia, defined as the age-related decrease in muscle mass, strength and physical performance, is associated with reduced bone mass and elevated low-grade inflammation. From a healthy aging perspective, interventions which overcome sarcopenia are clinically relevant. Accumulating evidence suggests that exogenous creatine supplementation has the potential to increase aging muscle mass, muscle performance, and decrease the risk of falls and possibly attenuate inflammation and loss of bone mineral. Therefore, the purpose of this review is to: (1) summarize the effects of creatine supplementation, with and without resistance training, in aging adults and discuss possible mechanisms of action, (2) examine the effects of creatine on bone biology and risk of falls, (3) evaluate the potential anti-inflammatory effects of creatine and (4) determine the safety of creatine supplementation in aging adults.

Effect of Menopausal Hormone Therapy on Bone Mineral Density in Chinese Women: A 2-Year, Prospective, Open-Label, Randomized-Controlled Trial

Background

This study was designed to explore the effect of menopausal hormone therapy (MHT) on bone mineral density (BMD) in Chinese women.

Material/Methods

This was a prospective, open-label, randomized-controlled clinical trial. We randomly assigned 123 postmenopausal women to 3 groups: group A received 0.625 mg conjugated equine estrogen (CEE) plus 100 mg micronized progesterone (MP), group B received 0.3 mg CEE daily plus 100 mg MP, and group C received 0.625 mg CEE daily plus 10 mg dydrogesterone (DHG). All subjects received a 2-year intervention and drugs were given in a continuous sequential pattern.

Results

Ninety-six patients were followed up. At 1 year, groups A and B gained 2.31% and 1.95% BMD, respectively (P<0.01); at 2 years, groups B and C gained 2.37% and 4.15% BMD (P<0.01) respectively. At 2 years, group A gained 3.28% BMD in the femoral neck and 3.77% BMD in Ward’s triangle (P<0.05). At 1 year, group B lost 2.14% BMD in the trochanter and 1.20% BMD in the total hip (P<0.05); at 2 years, group B lost 1.51% BMD in the total hip (P<0.01). ALP, Ca, P, and Ca/Cr levels were all decreased in the 3 groups (P<0.05). The changes in Cr level at 1 and 2 years were not significant when compared with baseline in all groups (P>0.05).

Conclusions

Both lower-dose and standard-dose CEE increased lumbar BMD, sustain femoral neck BMD, and Ward’s triangle BMD, while there was a reduced bone turnover rate. Standard-dose CEE combined with MP can increase BMD at these 2 sites. CEE combined with MP is recommended because it has better clinical benefits.

The potential therapeutic effects of creatine supplementation on body composition and muscle function in cancer

Low muscle mass in individuals with cancer has a profound impact on quality of life and independence and is associated with greater treatment toxicity and poorer prognosis. Exercise interventions are regularly being investigated as a means to ameliorate treatment-related adverse effects, and nutritional/supplementation strategies to augment adaptations to exercise are highly valuable. Creatine (Cr) is a naturally-occurring substance in the human body that plays a critical role in energy provision during muscle contraction. Given the beneficial effects of Cr supplementation on lean body mass, strength, and physical function in a variety of clinical populations, there is therapeutic potential in individuals with cancer at heightened risk for muscle loss. Here, we provide an overview of Cr physiology, summarize the evidence on the use of Cr supplementation in various aging/clinical populations, explore mechanisms of action, and provide perspectives on the potential therapeutic role of Cr in the exercise oncology setting.

Assessing the Associations of Blood Metabolites With Osteoporosis: A Mendelian Randomization Study

Context

Osteoporosis is a metabolic bone disease. The effect of blood metabolites on the development of osteoporosis remains elusive.

Objective

To explore the relationship between blood metabolites and osteoporosis.

Design and Methods

We used 2286 unrelated white subjects for the discovery samples and 3143 unrelated white subjects from the Framingham Heart Study (FHS) for the replication samples. The bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry. Genome-wide single nucleotide polymorphism (SNP) genotyping was performed using Affymetrix Human SNP Array 6.0 (for discovery samples) and Affymetrix SNP 500K and 50K array (for FHS replication samples). The SNP sets significantly associated with blood metabolites were obtained from a reported whole-genome sequencing study. For each subject, the genetic risk score of the metabolite was calculated from the genotype data of the metabolite-associated SNP sets. Pearson correlation analysis was conducted to evaluate the potential effect of blood metabolites on the variations in bone phenotypes; 10,000 permutations were conducted to calculate the empirical P value and false discovery rate.

Results

We analyzed 481 blood metabolites. We identified multiple blood metabolites associated with hip BMD, such as 1,5-anhydroglucitol (Pdiscovery < 0.0001; Preplication = 0.0361), inosine (Pdiscovery = 0.0018; Preplication = 0.0256), theophylline (Pdiscovery = 0.0048; Preplication = 0.0433, gamma-glutamyl methionine (Pdiscovery = 0.0047; Preplication = 0.0471), 1-linoleoyl-2-arachidonoyl-GPC (18:2/20:4n6; Pdiscovery = 0.0018; Preplication = 0.0390), and X-12127 (Pdiscovery = 0.0002; Preplication = 0.0249).

Conclusions

Our results suggest a modest effect of blood metabolites on the variations of BMD and identified several candidate blood metabolites for osteoporosis.

Creatine Supplementation During Resistance Training Does Not Lead to Greater Bone Mineral Density in Older Humans: A Brief Meta-Analysis

Creatine supplementation during resistance training has potential beneficial effects on properties of bone in aging adults. We systematically reviewed randomized controlled trials (RCTs) investigating the effect of creatine supplementation combined with resistance training on bone mineral density (BMD) in aging adults. We searched PubMed and SPORTDiscus databases and included RCTs of ≥3 months duration that examined the combined effect of creatine and resistance training on bone mineral in adults >50 years of age or postmenopausal. Meta-analyses were performed when applicable trials were available on whole body and clinically important bone sites. Five trials met inclusion criteria with a total of 193 participants. Two of the studies reported significant benefits of creatine supplementation and resistance training compared to resistance training alone on bone. Meta-analyses revealed no greater effect of creatine and resistance training compared to resistance training alone on whole body BMD (MD: 0.00, 95% CI −0.01 to 0.01, p = 0.50), hip BMD (MD −0.01, 95% CI −0.02 to 0.01, p = 0.26), femoral neck BMD (MD 0.00, 95% CI −0.01 to 0.01, p = 0.71), and lumbar spine BMD (MD 0.01, 95% CI −0.01 to 0.03, p = 0.32). In conclusion, there is a limited number of RCTs examining the effects of creatine supplementation and resistance training on BMD in older adults. Our meta-analyses revealed no significant effect on whole body, hip, femoral neck, or lumbar spine BMD when comparing creatine and resistance training to resistance training alone. Future longer term (>12 month) trials with higher resistance training frequencies (≥3 times per week) is warranted.

Creatine Supplementation Does Not Prevent the Development of Alcoholic Steatosis

BACKGROUND

Alcohol-induced reduction in the hepatocellular S-adenosylmethionine (SAM):S-adenosylhomocysteine (SAH) ratio impairs the activities of many SAM-dependent methyltransferases. These impairments ultimately lead to the generation of several hallmark features of alcoholic liver injury including steatosis. Guanidinoacetate methyltransferase (GAMT) is an important enzyme that catalyzes the final reaction in the creatine biosynthetic process. The liver is a major site for creatine synthesis which places a substantial methylation burden on this organ as GAMT-mediated reactions consume as much as 40% of all the SAM-derived methyl groups. We hypothesized that dietary creatine supplementation could potentially spare SAM, preserve the hepatocellular SAM:SAH ratio, and thereby prevent the development of alcoholic steatosis and other consequences of impaired methylation reactions.

METHODS

For these studies, male Wistar rats were pair-fed the Lieber-DeCarli control or ethanol (EtOH) diet with or without 1% creatine supplementation. At the end of 4 to 5 weeks of feeding, relevant biochemical and histological analyses were performed.

RESULTS

We observed that creatine supplementation neither prevented alcoholic steatosis nor attenuated the alcohol-induced impairments in proteasome activity. The lower hepatocellular SAM:SAH ratio seen in the EtOH-fed rats was also not normalized or SAM levels spared when these rats were fed the creatine-supplemented EtOH diet. However, a >10-fold increased level of creatine was observed in the liver, serum, and hearts of rats fed the creatine-supplemented diets.

CONCLUSIONS

Overall, dietary creatine supplementation did not prevent alcoholic liver injury despite its known efficacy in preventing high-fat-diet-induced steatosis. Betaine, a promethylating agent that maintains the hepatocellular SAM:SAH, still remains our best option for treating alcoholic steatosis.

Creatine supplementation in the aging population: effects on skeletal muscle, bone and brain

This narrative review aims to summarize the recent findings on the adjuvant application of creatine supplementation in the management of age-related deficits in skeletal muscle, bone and brain metabolism in older individuals. Most studies suggest that creatine supplementation can improve lean mass and muscle function in older populations. Importantly, creatine in conjunction with resistance training can result in greater adaptations in skeletal muscle than training alone. The beneficial effect of creatine upon lean mass and muscle function appears to be applicable to older individuals regardless of sex, fitness or health status, although studies with very old (>90 years old) and severely frail individuals remain scarce. Furthermore, there is evidence that creatine may affect the bone remodeling process; however, the effects of creatine on bone accretion are inconsistent. Additional human clinical trials are needed using larger sample sizes, longer durations of resistance training (>52 weeks), and further evaluation of bone mineral, bone geometry and microarchitecture properties. Finally, a number of studies suggest that creatine supplementation improves cognitive processing under resting and various stressed conditions. However, few data are available on older adults, and the findings are discordant. Future studies should focus on older adults and possibly frail elders or those who have already experienced an age-associated cognitive decline.

Effects of Creatine and Resistance Training on Bone Health in Postmenopausal Women

PURPOSE

Our primary purpose was to determine the effect of 12 months of creatine (Cr) supplementation during a supervised resistance training program on properties of bone in postmenopausal women.

METHODS

Participants were randomized (double-blind) into two groups: resistance training (3 d·wk) and Cr supplementation (0.1 g·kg·d) or resistance training and placebo (Pl). Our primary outcome measures were lumbar spine and femoral neck bone mineral density (BMD). Secondary outcome measures were total hip and whole-body BMD, bone geometric properties at the hip, speed of sound at the distal radius and tibia, whole-body lean tissue mass, muscle thickness, and bench press and hack squat strength. Forty-seven women (57 (SD, 6) yr; Cr, n = 23; Pl, n = 24) were randomized, with 33 analyzed after 12 months (Cr, n = 15; Pl, n = 18).

RESULTS

Cr attenuated the rate of femoral neck BMD loss (-1.2%; absolute change (95% confidence interval), -0.01 (-0.025 to 0.005) g·cm) compared with Pl (-3.9%; -0.03 (-0.044 to -0.017) g·cm; P < 0.05) and also increased femoral shaft subperiosteal width, a predictor of bone bending strength (Cr, 0.04 (-0.09 to 0.16) cm); Pl, -0.12 (-0.23 to -0.01) cm; P < 0.05). Cr increased relative bench press strength more than Pl (64% vs 34%; P < 0.05). There were no differences between groups for other outcome measures. There were no differences between groups for reports of serum liver enzyme abnormalities, and creatinine clearance was normal for Cr participants throughout the intervention.

CONCLUSIONS

Twelve months of Cr supplementation during a resistance training program preserves femoral neck BMD and increases femoral shaft superiosteal width, a predictor of bone bending strength, in postmenopausal women.

Effects of long-term low-dose dietary creatine supplementation in older women

OBJECTIVE

We aimed to investigate the effects of a one-year low-dose creatine supplementation trial on bone health, lean mass, and muscle function in older postmenopausal women.

METHODS

A double-blind, randomized, parallel-group, placebo controlled trial was conducted between November 2011 and November 2013 in Sao Paulo, Brazil. Postmenopausal osteopenic women were randomly allocated (1:1) into creatine (n=56; 1g/d) or placebo group (n=53; dextrose at same dose). At baseline and after one year of intervention, we assessed parameters of bone health, body composition, and muscle function. Blood parameters were also assessed before and after the intervention and adverse events were recorded throughout the trial. Possible differences in dietary intake were assessed by three 24-h dietary recalls.

RESULTS

Bone mineral density at lumbar spine, femoral neck, total femur, and whole body did not differ within- or between-groups. No significant changes in body weight, BMI, absolute and relative body fat, and body lean mass were observed. Muscle function, as assessed by timed-up-and-go and timed-stands tests, were not significantly changed within- or between-groups. Safety laboratory parameters remained unaltered.

CONCLUSION

A one-year low-dose creatine supplementation (1g/d) was free of adverse effects, but did not affect bone health parameters, lean mass, or muscle function in older women. Further studies with longer follow-up periods and higher doses of creatine supplementation are warranted. (Registered at clinicaltrials.gov as NCT01472393).

Exercise training, creatine supplementation, and bone health in ovariectomized rats

Evidence suggests that creatine may have some beneficial effects on bone. The study aimed to investigate the effects of exercise alone or combined with creatine on bone health in ovariectomized rats. Findings show that exercise, but not creatine, has an important role in improving bone health.

INTRODUCTION

The aim of this study was to investigate the effects of exercise training alone or combined with creatine supplementation on bone health parameters in ovariectomized rats.

METHODS

Wistar rats were randomly allocated into one of five groups: (i) sham-operated, (ii) ovariectomized non-trained placebo-supplemented, (iii) ovariectomized non-trained creatine-supplemented, (iv) ovariectomized exercise-trained placebo-supplemented, and (v) ovariectomized exercise-trained creatine-supplemented. Downhill running training and/or creatine supplementation (300 mg/kg body weight) were administered for 12 weeks. Bone mineral content (BMC), bone mineral density (BMD), and biomechanical and histomorphometric parameters were assessed.

RESULTS

No interaction effects were observed for BMC and BMD at whole body, femur, and lumbar spine (p > 0.05). Importantly, a main effect of training was detected for whole body BMC and BMD (p = 0.003 and p < 0.001, respectively), femoral BMC and BMD (p = 0.005 and p < 0.001, respectively), and lumbar spine BMC and BMD (p < 0.001 and p < 0.001, respectively), suggesting that the trained animals had higher bone mass, irrespective of creatine supplementation. Main effects of training were also observed for maximal load (p < 0.001), stiffness (p < 0.001), and toughness (p = 0.046), indicating beneficial effects of exercise training on bone strength. Neither a main effect of supplementation nor an interaction effect was detected for biomechanical parameters (p > 0.05). No main or interaction effects were observed for any of the histomorphometric parameters evaluated (p > 0.05).

CONCLUSIONS

Exercise training, but not creatine supplementation, attenuated ovariectomy-induced bone loss in this rat model.

Creatine supplementation and aging musculoskeletal health

Sarcopenia refers to the progressive loss of muscle mass and muscle function and is a contributing factor for cachexia, bone loss, and frailty. Resistance training produces several physiological adaptations which improve aging musculoskeletal health, such as increased muscle and bone mass and strength. The combination of creatine supplementation and resistance training may further lead to greater physiological benefits. We performed meta-analyses which indicate creatine supplementation combined with resistance training has a positive effect on aging muscle mass and upper body strength compared to resistance training alone. Creatine also shows promise for improving bone mineral density and indices of bone biology. The combination of creatine supplementation and resistance training could be an effective intervention to improve aging musculoskeletal health.

Alcohol consumption decreases rat hepatic creatine biosynthesis via altered guanidinoacetate methyltransferase activity

BACKGROUND

We have previously shown that decreased S-adenosylmethionine (SAM):S-adenosylhomocysteine (SAH) ratio generated in livers of alcohol-fed rats can impair the activities of many SAM-dependent methyltransferases. One such methyltransferase is guanidinoacetate methyltransferase (GAMT) that catalyzes the last step of creatine synthesis. As GAMT is the major utilizer of SAM, the purpose of the study was to examine the effects of ethanol (EtOH) on liver creatine levels and GAMT activity.

METHODS

Male Wistar rats were pair-fed the Lieber-DeCarli control and EtOH diet for 4 to 5 weeks. At the end of the feeding regimen, the liver, kidney, and blood were removed from these rats for subsequent biochemical analyses.

RESULTS

We observed ~60% decrease in creatine levels in the livers from EtOH-fed rats as compared to controls. The reduction in creatine levels correlated with lower SAM:SAH ratio observed in the livers of the EtOH-fed rats. Further, in vitro experiments with cell-free system and hepatic cells revealed it is indeed elevated SAH and lower SAM:SAH ratio that directly impairs GAMT activity and significantly reduces creatine synthesis. EtOH intake also slightly decreases the hepatocellular uptake of the creatine precursor, guanidinoacetate (GAA), and the GAMT enzyme expression that could additionally contribute to reduced liver creatine synthesis. The consequences of impaired hepatic creatine synthesis by chronic EtOH consumption include (i) increased toxicity due to GAA accumulation in the liver; (ii) reduced protection due to lower creatine levels in the liver, and (iii) reduced circulating and cardiac creatine levels.

CONCLUSIONS

Chronic EtOH consumption affects the hepatic creatine biosynthetic pathway leading to detrimental consequences not only in the liver but could also affect distal organs such as the heart that depend on a steady supply of creatine from the liver.

Creatine supplementation in fibromyalgia: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To investigate the efficacy and safety of creatine supplementation in fibromyalgia patients.

METHODS

A 16-week, randomized, double-blind, placebo-controlled, parallel-group trial was conducted. Fibromyalgia patients were randomly assigned to receive either creatine monohydrate or placebo in a double-blind manner. The patients were evaluated at baseline and after 16 weeks. Muscle function, aerobic conditioning, cognitive function, quality of sleep, quality of life, kidney function, and adverse events were assessed. Muscle phosphorylcreatine content was measured through (31) P magnetic resonance spectroscopy.

RESULTS

After the intervention, the creatine group presented higher muscle phosphorylcreatine content when compared with the placebo group (+80.3% versus -2.7%; P = 0.04). Furthermore, the creatine group presented greater muscle strength than the placebo group in the leg press and chest press exercises (+9.8% and +1.2% for creatine versus -0.5% and -7.2% for placebo, respectively; P = 0.02 and P = 0.002, respectively). Isometric strength was greater in the creatine group than in the placebo group (+6.4% versus -3.2%; P = 0.007). However, no general changes were observed in aerobic conditioning, pain, cognitive function, quality of sleep, and quality of life. Food intake remained unaltered and no side effects were reported.

CONCLUSION

Creatine supplementation increased intramuscular phosphorylcreatine content and improved lower- and upper-body muscle function, with minor changes in other fibromyalgia features. These findings introduce creatine supplementation as a useful dietary intervention to improve muscle function in fibromyalgia patients.

Influence of creatine supplementation on bone quality in the ovariectomized rat model: an FT-Raman spectroscopy study

The influence of creatine (Cr) supplementation on cortical and trabecular bone from ovariectomized rats was studied using FT-Raman spectroscopy. The intensity of organic-phase Raman bands was compared to mineral phase ones. Twenty-one female Wistar rats aged 3 months were divided into three groups (n = 7 per group): ovariectomized (OVX), ovariectomized treated with creatine (CRE) and sham-operated (SHAM) groups. Creatine supplementation (300 mg kg(-1) day(-1)) was provided for 8 weeks, starting 12 weeks after ovariectomy. FT-Raman spectroscopy was performed on the right medial femoral mid-shaft (cortical bone) and third lumbar vertebral body (trabecular bone). The integrated intensities of mineral phase (phosphate and carbonate bands at 959 and 1,071 cm(-1), respectively) and organic phase (amide I band at 1,665 cm(-1)) Raman bands were analyzed. The mineral-to-matrix (phosphate/amide I), carbonate-to-phosphate, and carbonate-to-amide I ratios were analyzed to assess bone quality. The phosphate content on trabecular bone was higher in the CRE group than the OVX group (p < 0.05). No significant changes in mineral or organic phases on cortical bone were observed. A radiographic assessment of bone density was encouraging as the same findings were showed by Raman intensity of phosphate from cortical (r(2) = 0.8037) and trabecular bones (r(2) = 0.915). Severe ovariectomy-induced bone loss was confirmed by FT-Raman spectroscopy. The results suggest that the chemical composition of trabecular bone tissue may be positively influenced by Cr supplementation after ovariectomy.

Creatine as a therapeutic strategy for myopathies

Myopathies are genetic or acquired disorders of skeletal muscle that lead to varying degrees of weakness, atrophy, and exercise intolerance. In theory, creatine supplementation could have a number of beneficial effects that could enhance function in myopathy patients, including muscle mass, strength and endurance enhancement, lower calcium levels, anti-oxidant effects, and reduced apoptosis. Patients with muscular dystrophy respond to several months of creatine monohydrate supplementation (~0.075-0.1 g/kg/day) with greater strength (~9%) and fat-free mass (~0.63 kg). Patients with myotonic dystrophy do not show as consistent an effect, possibly due to creatine transport issues. Creatine monohydrate supplementation shows modest benefits only at lower doses and possibly negative effects (cramping) at higher doses in McArdle's disease patients. Patients with MELAS syndrome show some evidence of benefit from creatine supplementation in exercise capacity, with the effects in patients with CPEO being less robust, again, possibly due to limited muscle creatine uptake. The evidence for side effects or negative impact upon serological metrics from creatine supplementation in all groups of myopathy patients is almost non-existent and pale in comparison to the very substantial and well-known side effects from our current chemotherapeutic interventions for some myopathies (i.e., corticosteroids).

Potential of creatine supplementation for improving aging bone health

Aging subsequently results in bone and muscle loss which has a negative effect on strength, agility, and balance leading to increased risks of falls, injuries, and fractures. Resistance training is an effective strategy for maintaining bone mass, possibly by increasing activity of cells involved in bone formation and reducing activity of cells involved in bone resorption. However, bone loss is still evident in older adults who have maintained resistance training for most of their life, suggesting that other factors such as nutrition may be involved in the aging bone process. Emerging evidence suggests that creatine supplementation, with and without resistance training, has the potential to influence bone biology. However, research investigating the longer-term effects of creatine supplementation and resistance training on aging bone is limited.

Low-dose creatine combined with protein during resistance training in older men

PURPOSE

To determine whether low-dose creatine and protein supplementation during resistance training (RT; 3 d x wk(-1); 10 wk) in older men (59-77 yr) is effective for improving strength and muscle mass without producing potentially cytotoxic metabolites (formaldehyde).

METHODS

Older men were randomized (double-blind) to receive 0.1 g x kg(-1) creatine + 0.3 g x kg(-1) protein (CP; n = 10), creatine (C; n = 13), or placebo (PLA; n = 12) on training days. Measurements before and after RT included lean tissue mass (air-displacement plethysmography), muscle thickness (ultrasound) of elbow, knee, and ankle flexors and extensors, leg and bench press strength, and urinary indicators of cytotoxicity (formaldehyde), myofibrillar protein degradation [3-methylhistidine (3-MH)],and bone resorption [cross-linked N-telopeptides of type I collagen (NTx)].

RESULTS

Subjects in C and CP groups combined experienced greater increases in body mass and total muscle thickness than PLA (P < 0.05). Subjects who received CP increased lean tissue mass (+5.6%) more than C (+2.2%) or PLA (+1.0%; P < 0.05) and increased bench press strength (+25%) to a greater extent than C and PLA combined (+12.5%; P < 0.05). CP and C did not differ from PLA for changes in formaldehyde production (+24% each). Subjects receiving creatine (C and CP) experienced a decrease in 3-MH by 40% compared with an increase of 29% for PLA (P < 0.05) and a reduction in NTx (-27%) versus PLA (+13%; P = 0.05).

CONCLUSIONS

Low-dose creatine combined with protein supplementation increases lean tissue mass and results in a greater relative increase in bench press but not leg press strength. Low-dose creatine reduces muscle protein degradation and bone resorption without increasing formaldehyde production.

Conjugated linoleic acid prevents growth attenuation induced by corticosteroid administration and increases bone mineral content in young rats

Corticosteroids are a common therapy in many disease states, despite frequent and potentially serious side effects. Nutritional supplementation with conjugated linoleic acid (CLA) has been shown to increase fat-free mass, whereas supplementation with n-3 and n-6 fatty acids has been shown to increase bone mineral density (BMD). To determine whether CLA can attenuate the side effects of 8 weeks of corticosteroid administration, we randomized twenty-four 5-week-old male Sprague-Dawley rats into 1 of 4 groups: control; control + methylprednisolone (7 mg.kg-1.week-1); CLA diet (1% CLA w/w); or CLA plus methylprednisolone. Body composition, bone mineral content (BMC), and BMD were assessed with dual-energy X-ray absorptiometry at the onset and at the end of the 8-week intervention. The mechanical properties of bone were determined using 3-point femur bending at the end of the intervention. Methylprednisolone resulted in an attenuation of the increase in body mass and lean mass over the 8 weeks (p < 0.05). CLA prevented the methylprednisolone-induced attenuation of body mass and lean mass accumulation. CLA also resulted in a greater increase in BMC (p < 0.05) in the lumbar spine. The energy at failure of the isolated femurs was increased with CLA (p < 0.05). Dietary CLA prevents many of the growth- and bone-related side effects arising from 8 weeks of corticosteroid administration, results in greater increases in BMC and BMD, and can contribute to an improvement in some of the mechanical properties of bone.

Creatine monohydrate attenuates body fat accumulation in children with acute lymphoblastic leukemia during maintenance chemotherapy

BACKGROUND

Corticosteroids are an important component of the treatment of acute lymphoblastic leukemia (ALL), with known significantly negative effects on bone and muscle. Creatine monohydrate (CrM) supplementation may be an adjunctive therapeutic strategy to attenuate some of these adverse effects.

PROCEDURE

Nine children with ALL in the maintenance phase of treatment on the Dana-Farber Cancer Institute (DFCI) protocol 2000-2001 were treated with CrM (0.1 g/kg/day) for two sequential periods of 16 weeks (16 weeks treat > 6 weeks wash-out > 16 weeks treat). A cohort of children (N = 50) who were receiving the same chemotherapy at the same time served as natural history controls. Measurements included height, weight, body mass index (BMI), and lumbar spine bone mineral density (LS-BMD), whole body bone mineral content (WB-BMC), fat-free mass (FFM), and percent body fat (%BF) using dual-energy X-ray absorptiometry.

RESULTS

Despite the long course of corticosteroid treatment for ALL, children showed significant increases in height, LS-BMD, WB-BMC and FFM over approximately 38 weeks (P < 0.05) during the study. There was an increase in BMI over time, but children taking CrM had a reduction, while the natural history group showed an increase in % BF (P < 0.05 for interaction).

CONCLUSIONS

Children with ALL treated with corticosteroids as part of a maintenance protocol of chemotherapy showed an increase in % BF that was attenuated by CrM supplementation.

The potential benefits of creatine and conjugated linoleic acid as adjuncts to resistance training in older adults

Human aging is associated with a significant reduction in muscle mass (sarcopenia) resulting in muscle weakness and functional limitations in the elderly. Sarcopenia has been associated with mitochondrial dysfunction and the accumulation of mtDNA deletions. Resistance training increases muscle strength and size and can increase mitochondrial capacity and decrease oxidative stress in older adults. Creatine monohydrate (CrM) and conjugated linoleic acid (CLA) have biological effects that could enhance some of the beneficial effects of resistance training in older adults (i.e., up arrow fat-free mass, down arrow total body fat). We have completed two resistance-training studies with CrM alone and CrM+CLA supplementation in older adults to evaluate the independent effects of exercise and dietary supplements, as well as their interactive effects. Our studies, and several others, have found that CrM enhanced the resistance exercise mediated gains in fat-free mass and strength. More recently, we found that the addition of CLA also lead to a significant reduction of body fat after six months of resistance training in older adults. Older adults have fewer wild-type mtDNA copies and higher amounts of mtDNA deletions as compared with younger adults in mature skeletal muscle; however, these deletions are not seen in the satellite cell-derived myoblast cultures. These findings, and the fact that mtDNA deletions are lower and wild-type mtDNA copy number is higher after resistance training in older adults, suggests that activation of satellite cells secondary to resistance exercise-induced muscle damage can dilute or "shift" the proportion of mtDNA genotype towards that of a younger adult. Recent evidence suggests that CrM supplementation in combination with strength training can enhance satellite cell activation and total myonuclei number per muscle fiber in young men. Future studies are required to determine whether the mitochondrial adaptations to resistance exercise in older adults are further enhanced with CrM supplementation and whether this is due to increased recruitment of satellite cells. It will also be important to determine whether these changes are maintained over a longer time period.

Creatine and creatine kinase in health and disease--a bright future ahead?

Many links are reported or suspected between the functioning of creatine, phosphocreatine, the creatine kinase isoenzymes or the creatine biosynthesis enzymes on one hand, and health or disease on the other hand. The aim of the present book was to outline our current understanding on many of these links. In this chapter, we summarize the main messages and conclusions presented in this book. In addition, we refer to a number of recent publications that highlight the pleiotropy in physiological functions of creatine and creatine kinase, and which suggest that numerous discoveries on new functions of this system are still ahead of us. Finally, we present our views on the most promising future avenues of research to deepen our knowledge on creatine and creatine kinase. In particular, we elaborate on how state-of-the-art high-throughput analytical ("omics") technologies and systems biology approaches may be used successfully to unravel the complex network of interdependent physiological functions related to creatine and creatine kinase.