Interleukin-6 −174G/C gene polymorphism affects muscle damage response to acute eccentric resistance exercise in elderly obese women

Recovery from Resistance Exercise in Older Adults: A Systematic Scoping Review

BACKGROUND

Resistance exercise is recommended for maintaining muscle mass and strength in older adults. However, little is known about exercise-induced muscle damage and recovery from resistance exercise in older adults. This may have implications for exercise prescription. This scoping review aimed to identify and provide a broad overview of the available literature, examine how this research has been conducted, and identify current knowledge gaps relating to exercise-induced muscle damage and recovery from resistance exercise in older adults.

METHODS

Studies were included if they included older adults aged 65 years and over, and reported any markers of exercise-induced muscle damage after performing a bout of resistance exercise. The following electronic databases were searched using a combination of MeSH terms and free text: MEDLINE, Scopus, Embase, SPORTDiscus and Web of Science. Additionally, reference lists of identified articles were screened for eligible studies. Data were extracted from eligible studies using a standardised form. Studies were collated and are reported by emergent theme or outcomes.

RESULTS

A total of 10,976 possible articles were identified and 27 original research articles were included. Findings are reported by theme; sex differences in recovery from resistance exercise, symptoms of exercise-induced muscle damage, and biological markers of muscle damage.

CONCLUSIONS

Despite the volume of available data, there is considerable variability in study protocols and inconsistency in findings reported. Across all measures of exercise-induced muscle damage, data in women are lacking when compared to males, and rectifying this discrepancy should be a focus of future studies. Current available data make it challenging to provide clear recommendations to those prescribing resistance exercise for older people.

IL-6 and HSPA1A Gene Polymorphisms May Influence the Levels of the Inflammatory and Oxidative Stress Parameters and Their Response to a Chronic Swimming Training

The aim of the study was to evaluate whether the most common polymorphisms in the IL-6 and HSP70 genes affect the circulating heat shock protein 70 (HSP70), as well as inflammatory and prooxidant-antioxidant parameters in healthy men undergoing chronic endurance training. The subjects were randomly assigned to a 12-week swimming training (ST group) or control group (CON). Fasting blood samples were collected pre- and post-study period to assessment: superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, serum levels of lipid hydroperoxides (LHs), tumor necrosis factor α (TNFα), and HSP70. Subjects were genotyped for IL-6-174G/C, HSPA1A + 190 G/C and HSPA1B + 1538 A/G single nucleotide polymorphisms (SNPs) by real-time PCR. After a 12-week study period, a decrease in TNFα, HSP70, and GPx was observed in the ST group, but not the CON group. IL-6 SNP affected serum TNFα levels (main effect of genotype). Higher TNFα levels (pre- and post-study period) was observed in CC CON than in other IL-6 genotypes of CON and ST groups. However, a post-training decrease in TNFα was observed in both GG and CC IL-6 genotypes of ST group. In turn, only GG IL-6 genotype of the ST group was related to a post-training decrease in HSP70 (main time and genotype interaction). Moreover, pre- and post-training LHs were lower in GG than GC/CC HSPA1A genotypes of the ST group (main genotype effect). In conclusion, polymorphisms within the IL-6 and HSPA1A genes seem to affect baseline levels of some inflammatory parameters and prooxidant-antioxidant status and/or their changes after chronic swimming training. However, the results should be confirmed in a study with a larger sample size, one that includes individuals with sedentary lifestyles.

Genetic Basis for the Dominance of Israeli Long-Distance Runners of Ethiopian Origin

ABSTRACT

Ben-Zaken, S, Meckel, Y, Nemet, D, Kassem, E, and Eliakim, A. Genetic basis for the dominance of Israeli long-distance runners of Ethiopian origin. J Strength Cond Res 35(7): 1885-1896, 2021-Israeli long-distance runners of Ethiopian origin have a major influence on the track and field long-distance record table. The aim of this study was to determine whether genetic characteristics contribute to this long-distance dominance. We assessed polymorphisms in genes related to endurance (PPARD T/C), endurance trainability (ACSL A/G), speed (ACTN3 R/X), strength (AGT T/C), and the recovery from training (MTC1 A/T and IL6 G/C) among top Israeli long-distance runners of Ethiopian origin (n = 37), Israeli non-Ethiopian origin runners of Caucasian origin (n = 76), and Israeli nonathletic controls (n = 55). Israeli runners of Ethiopian origin had a greater frequency of the PPARD CC + PARGC1A Gly/Gly polymorphism, associated with improved endurance performance, compared with Israeli runners of non-Ethiopian origins (24 vs. 3%, respectively, p < 0.01); a lower frequency of the ACSL AA polymorphism, favoring endurance trainability (8 vs. 20%, respectively, p < 0.05); a greater frequency of the ACTN3 RR polymorphism, associated with sprint performance (35 vs. 20%, respectively, p < 0.05); a greater frequency of the MCT1 AA genotype, associated with improved lactate transport (65 vs. 45%, respectively, p < 0.05); and a lower frequency of IL-6 174C carriers, associated with reduced postexercise muscle damage (27 vs. 40%, respectively, p < 0.01). There was no difference in the frequency of AGT T/C gene polymorphism between the long-distance runners of Ethiopian and non-Ethiopian origin. Frequencies of PPARD CC + PARGC1A Gly/Gly, MCT1 AA, IL-6 174C, and AGT polymorphism were significantly favorable among Ethiopian, but not among non-Ethiopian, origin runners compared with controls. Taken together, results suggest that genetically, the dominance of Israeli long-distance runners of Ethiopian origin relates not only to endurance polymorphisms but also to polymorphisms associated with enhanced speed performance and better training recovery ability.

Methodological Approach of the Iron and Muscular Damage: Female Metabolism and Menstrual Cycle during Exercise Project (IronFEMME Study)

Abstract

Background: The increase in exercise levels in the last few years among professional and recreational female athletes has led to an increased scientific interest about sports health and performance in the female athlete population. The purpose of the IronFEMME Study described in this protocol article is to determine the influence of different hormonal profiles on iron metabolism in response to endurance exercise, and the main markers of muscle damage in response to resistance exercise; both in eumenorrheic, oral contraceptive (OC) users and postmenopausal well-trained women. Methods: This project is an observational controlled randomized counterbalanced study. One hundered and four (104) active and healthy women were selected to participate in the IronFEMME Study, 57 of which were eumenorrheic, 31 OC users and 16 postmenopausal. The project consisted of two sections carried out at the same time: iron metabolism (study I) and muscle damage (study II). For the study I, the exercise protocol consisted of an interval running test (eight bouts of 3 min at 85% of the maximal aerobic speed), whereas the study II protocol was an eccentric-based resistance exercise protocol (10 sets of 10 repetitions of plate-loaded barbell parallel back squats at 60% of their one repetition maximum (1RM) with 2 min of recovery between sets). In both studies, eumenorrheic participants were evaluated at three specific moments of the menstrual cycle: early-follicular phase, late-follicular phase and mid-luteal phase; OC users performed the trial at two moments: withdrawal phase and active pill phase. Lastly, postmenopausal women were only tested once, since their hormonal status does not fluctuate. The three-step method was used to verify the menstrual cycle phase: calendar counting, blood test confirmation, and urine-based ovulation kits. Blood samples were obtained to measure sex hormones, iron metabolism parameters, and muscle damage related markers. Discussion: IronFEMME Study has been designed to increase the knowledge regarding the influence of sex hormones on some aspects of the exercise-related female physiology. Iron metabolism and exercise-induced muscle damage will be studied considering the different reproductive status present throughout well-trained females’ lifespan.

Trial registration

The study was registered at Clinicaltrials.gov NCT04458662 on 2 July 2020.

The combined frequencies of the IL-6 G-174C and IGFBP3 A-202C polymorphisms among swimmers and runners

Previous studies have demonstrated that compared to runners, swimmers carry a higher prevalence of the IL-6 -174C polymorphism and lower single nucleotide polymorphism frequencies of the IGF system.

PURPOSE

The aim of the present study was to assess the combined frequency of the IL-6 -174G/C and IGFBP3 -202A/C polymorphisms among track and field athletes and swimmers.

METHODS

Track and field athletes were divided into long-distance runners (major event 5000 m-marathon, n = 63) and power athletes (major event 100-200 m sprints and long jump, n = 67). Swimmers were divided into long-distance swimmers (major event: 400-1500 m, n = 50), and short-distance swimmers (major event: 50-100 m, n = 43). All participants had achieved results that ranked them among the top all-time Israeli athletes in their event, and competed at national and/or international level on a regular basis.

RESULTS

Carrying both IL-6C and IGFBP3C mutations was significantly greater among long-distance swimmers (LDS - 44%) compared to long distance runners (LDR - 21%, p < .01), and among short distance swimmers (SDS - 49%) compared to sprinters and jumpers (S/J - 28%, p < .05). Among runners, the prevalence of those not carrying either of the two mutations was significantly higher among LDR (25%) compared to S/J (10%, p < .03).

CONCLUSION

The prevalence of carrying both IL-6C and IGFBP3C mutations was significantly higher among the swimmers compared to runners. It is possible that carrying the IGFBP3C polymorphism is required to compensate for the potential genetically non-beneficial effects of a higher IL-6C genotype and an attenuated IGF system among the swimmers.

The impact of sarcopenic obesity on inflammation, lean body mass, and muscle strength in elderly women

Objective

The objective of this study was to apply the newly standardized definition for sarcopenia from the Foundation for the National Institutes of Health (FNIH) and the current definition for obesity to 1) determine the prevalence of sarcopenic obesity (SO) in obese elderly women; 2) compare the muscle strength, lean body mass, and markers of inflammation between obese elderly women with SO and nonsarcopenic obesity (NSO), and 3) elucidate the relationship between appendicular lean mass adjusted for body mass index (aLM/BMI) with muscle strength, lean body mass, and obesity indices.

Methods

A total of 64 elderly obese women (age: 68.35±6.04 years) underwent body composition analysis by dual-energy X-ray absorptiometry. Participants were classified into two groups according to the definition of SO and NSO. Blood samples were collected for total cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein, uric acid, urea, interleukin-6 (IL-6), glucose, and creatine kinase (CK) measurements.

Results

The SO group presented a significantly greater BMI, fat (%), glucose, a marginal trend toward significance for uric acid, and IL-6 compared to the NSO group. In addition, the SO group displayed lower values for muscle strength and lean body mass. From a correlation standpoint, a higher aLM/BMI was positively associated with lean body mass and muscle strength and negatively associated with a lower BMI and percentage body fat.

Conclusion

The definition criteria from FNIH and obesity permit the ability to illustrate the prevalence and identify SO in elderly women with low muscle mass, low muscle strength, and impaired markers of inflammation.

Increased Prevalence of the IL-6-174C Genetic Polymorphism in Long Distance Swimmers

The IL-6 -174G/C single nucleotide polymorphism (SNP) functionally affects IL-6 activity, with the G-allele associated with increased IL-6 levels. The C-allele was found to be associated with exercise-induced skeletal muscle damage. The aim of the present study was to examine the association between the IL-6 -174G/C polymorphism and athletic performance among elite swimmers and runners. The study sample included 180 track and field athletes and 80 swimmers. Track and field athletes were assigned to three sub-groups: long-distance runners, middle-distance runners and short-distance runners. Swimmers were assigned to two subgroups: long-distance swimmers and short-distance swimmers. The control group consisted of 123 non-athletic healthy individuals. Genomic DNA was extracted from peripheral blood following a standard protocol. Genotyping was performed using polymerase chain reaction (PCR). The CC genotype and C-allele frequency were significantly higher in the long-distance swimmers (18 and 43%, respectively) compared to the long-distance runners (3 and 14%, respectively, p < 0.001); middle-distance runners (4 and 22%, respectively, p < 0.001); and controls (5 and 19%, respectively, p < 0.001). In addition, the CC genotype and C-allele frequency were significantly higher (p < 0.001) in long-distance swimmers compared to short-distance swimmers (18 versus 5% and 43 versus 29% for the CC genotype and C-allele frequency, respectively). The higher frequency of the C-allele and CC genotype among long-distance swimmers suggests that the rarity of exercise-associated rhabdomyolysis among swimmers is probably related to other sports-specific or water-related protective mechanisms. It is possible that swimming selection in talented endurance athletes who are C-allele carriers represents an example of genetically-dependent sports selection.

Genetic variation and exercise-induced muscle damage: implications for athletic performance, injury and ageing

Prolonged unaccustomed exercise involving muscle lengthening (eccentric) actions can result in ultrastructural muscle disruption, impaired excitation-contraction coupling, inflammation and muscle protein degradation. This process is associated with delayed onset muscle soreness and is referred to as exercise-induced muscle damage. Although a certain amount of muscle damage may be necessary for adaptation to occur, excessive damage or inadequate recovery from exercise-induced muscle damage can increase injury risk, particularly in older individuals, who experience more damage and require longer to recover from muscle damaging exercise than younger adults. Furthermore, it is apparent that inter-individual variation exists in the response to exercise-induced muscle damage, and there is evidence that genetic variability may play a key role. Although this area of research is in its infancy, certain gene variations, or polymorphisms have been associated with exercise-induced muscle damage (i.e. individuals with certain genotypes experience greater muscle damage, and require longer recovery, following strenuous exercise). These polymorphisms include ACTN3 (R577X, rs1815739), TNF (-308 G>A, rs1800629), IL6 (-174 G>C, rs1800795), and IGF2 (ApaI, 17200 G>A, rs680). Knowing how someone is likely to respond to a particular type of exercise could help coaches/practitioners individualise the exercise training of their athletes/patients, thus maximising recovery and adaptation, while reducing overload-associated injury risk. The purpose of this review is to provide a critical analysis of the literature concerning gene polymorphisms associated with exercise-induced muscle damage, both in young and older individuals, and to highlight the potential mechanisms underpinning these associations, thus providing a better understanding of exercise-induced muscle damage.

Classification of pro-inflammatory status for interleukin-6 affects relative muscle strength in obese elderly women

BACKGROUND

Obesity, defined by an excess amount of body fat or a percent body fat higher than 30 % for women is a complex chronic disorder with multifactorial etiology and is accompanied by chronic low-grade inflammation, which results in elevated pro-inflammatory cytokines.

AIMS

The aim of this study was to compare muscle strength between high and low pro-inflammatory status in obese elderly women and to verify the relationship of IL-6 with muscle strength and fat-free mass.

METHODS

Eighty-nine elderly women (age 69.47 ± 6.07 years; body mass 64.70 ± 12.04 kg; height 1.52 ± 0.06 m; body mass index 27.78 ± 4.75 kg/m(2)) were divided into two groups: high and low inflammatory status for IL-6. Lower limb muscle strength was tested using bilateral leg extension with the ten repetitions maximum test, IL-6 was measured by ELISA and body composition by dual-energy X-ray absorptiometry.

RESULTS

Women classified from the high pro-inflammatory status presented lower relative muscle strength (P = 0.056) when compared with the low inflammatory status group, with no differences for absolute muscle strength (P = 0.18). There was a significant negative correlation of IL-6 with relative muscle strength (P = 0.03, R = -0.22) and a considerable trend toward significance (P = 0.06, R = -0.19) and negative association with fat-free mass (P = 0.84, R = -0.02).

CONCLUSIONS

This study provides insights that a high pro-inflammatory status in sedentary obese elderly women might impair muscle strength and negatively affect fat-free mass. Thus, elderly women classified with high pro-inflammatory status for IL-6 should receive further health care attention to prevent this deleterious condition.

The relationship of creatine kinase variability with body composition and muscle damage markers following eccentric muscle contractions

[Purpose]

The purpose of the study was to investigate the relationship between CK variability and body composition and muscle damage markers following eccentric exercise.

[Methods]

Total 119 healthy male subjects were recruited to perform 50 eccentric contractions consisted of 2 sets of 25 contractions. Then, blood creatine kinase (CK) activity was analyzed to divide into three groups based on their CK activity levels. Maximum isometric strength (MIS), muscle soreness (SOR) and body composition data were obtained before and after exercise.

[Results]

The results showed that high CK responders had a significant decrease in MIS (p<0.001) and greater SOR (p<0.01) following eccentric exercise compared to low CK responders. Percent body fat was also higher in high responders compared to low responders (p=0.014). Peak CK activity was significantly correlated with MIS and SOR but no correlation with % body fat, muscle mass, and body mass index.

[Conclusion]

CK variability following eccentric exercise is closely related to MIS and SOR and % body fat may be a potent factor for CK variability.

Endothelial nitric oxide synthase Glu298Asp gene polymorphism influences body composition and biochemical parameters but not the nitric oxide response to eccentric resistance exercise in elderly obese women

Both endothelial nitric oxide synthase (eNOS) gene polymorphism and nitric oxide (NO) are involved in important cardiovascular, muscular and inflammatory physiological mechanisms during ageing and response to exercise. The aim of this study was to investigate the NO kinetic response following an acute eccentric resistance exercise (ERE) session and the possible effect of the Glu298Asp eNOS gene polymorphism in elderly obese women. Eighty-seven women (age 69·4 ± 6·1 years, body weight 74·9 ± 12·7 kg, height 151·9 ± 6·0 cm and BMI 32·5 ± 5·7 kg m^-2 ) completed seven sets of ten eccentric repetitions at 110% of the ten repetitions maximum (10RM). NO concentrations remained elevated up to 48 h following the acute ERE session as compared with baseline, for GG and GT/TT groups (P<0·05), with no differences between genotypes. The GG genotype group had higher body weight, prevalence of obesity (BMI classification - 81% versus 56%), BMI and higher relative muscle strength, while they had significantly lower triglycerides, VLDL and urea concentrations as compared with TT/TG group. In conclusion, NO remains elevated for up to 48 h after an acute ERE session, without genotype interaction. The TT/TG genotype had a negative impact on triglycerides, VLDL and urea concentrations. Thus, T carriers should increase their attention to cardiovascular risk factor and metabolic disorders.

Acute eccentric resistance exercise decreases matrix metalloproteinase activity in obese elderly women

The association of ageing with obesity commits elderly women and has been correlated with multiple degenerative processes, which could be occasioned by an enhancing in levels of matrix metalloproteinase-2 and metalloproteinase-9 (MMPs) as well by an cytokine unbalance that included an enhancing on interleukin-6 (IL-6). Furthermore, other factors could be also related to degenerative process, as they could be reduced by eccentric resistance exercise (ERE), which seems particularly important to initiate resistance training in obese older adults. In this view, this study aims to determinate the effects of an acute ERE session on serum MMP-2, MMP-9 and IL-6 in elderly obese women. Ten elderly obese women participated in this study and completed a 10 repetitions maximum test (10 RM) utilizing leg extension exercise. Subjects then completed an acute ERE session consisting of seven sets of 10 repetitions at 110% of 10 RM with a rest of 3 min between sets. Blood samples were collected before, immediately after, 3, 24 and 48 h following the ERE session. Zymograms were utilized to measure the MMP-2 and MMP-9 enzymes from all individuals. Moreover, IL-6 concentration was also determinated. After ERE session, MMP-2 and MMP-9 decreased, remaining significantly below baseline values after 48 h (P<0·05). Although not statistically significant, there was a tendency for IL-6 to decrease 48 h after the ERE when compared with 3 h (P = 0·06). An acute ERE session decreases MMP-9, MMP-2 and IL-6 in elderly obese women, possibly indicating a transient protection against the low grade inflammation present in this specific population.