Age-Related Decline in Sex-Specific Differences (PDF)

10/4/2023 Age-related Decline Considerations of sex-specific differences Jenn(ifer) Jakobi PhD UBC Okanagan [email protected] Who am I and what do I do ? Understand sex-specific age related decline to support functional Independence Support needs and choice of older women and men to age in...

10/4/2023 Age-related Decline Considerations of sex-specific differences Jenn(ifer) Jakobi PhD UBC Okanagan [email protected] Who am I and what do I do ? Understand sex-specific age related decline to support functional Independence Support needs and choice of older women and men to age in place. Provide equitable and inclusive learning and working environments for underrepresented persons in STEM. 1 10/4/2023 Acknowledge work of…. 2020 2022 2023 2023 2018 2019 2017 2015 Overview • Lay the groundwork • Canadian Older Adults • Sex and Gender Research • Age-related change in NM System • Frailty and exercise • sex-specific age-related decline & frailty • Moving forward • Knowledge gaps & opportunities 2 10/4/2023 Canada - Aging BC 20% of population is 65+years Is sex and gender the same? A. Yes B. No 3 10/4/2023 Sex-Specific Science Gender Sex socially constructed roles, behaviours, expressions and identities of men and women biological attributes Physical features Hormones Gene expression Anatomy Better Science for meaningful research https://cihr‐irsc.gc.ca/e/49347.html Sex-Specific Aging • Every cell is sexed & every person is gendered. • In Canada men typically die younger than women, yet more women than men struggle with chronic illnesses and live longer ? Health-survival paradox Why? • The more we understand how sex and gender affect health, the more we can improve health and well-being for everyone. 4 10/4/2023 Sex-Specific Aging 213,000 85‐89 years 312,000 85‐89 years 1.3mil 30‐34 years https://www150.statcan.gc.ca/n1/pub/71‐607‐x/71‐607‐ x2020018‐eng.htm Sex-Specific Aging 99:100 males:females @ 50 years 68:99 males:females @85‐89 years https://www150.statcan.gc.ca/n1/pub/71‐607‐x/71‐607‐ x2020018‐eng.htm 5 10/4/2023 Sex-Specific Aging Research Devries MC, Jakobi JM. Importance of considering sex and gender in exercise and nutrition research. Appl Physiol Nutr Metab. 2021 Jun;46(6):iii‐vii. doi: 10.1139/apnm‐2021‐0298. PMID: 34125618. Age-related Change in Contractile Properties 6 10/4/2023 Age-related Change in Contractile Properties Young Old 5N Age-related Sex-Specific - animal models Chan, S., & Head, S. I. (2010). Age‐and gender‐related changes in contractile properties of non‐atrophied EDL muscle. PLoS One, 5(8), e12345. 7 10/4/2023 Muscle & Strength Leg Strength Arm Strength Haynes et al. Appl Physiol Nutr Metab. 2020 Nov;45(11):1185‐1196. doi: 10.1139/apnm‐2020‐0081. Knee flexors Why is MVC lower? Jakobi & Rice 1999 8 10/4/2023 Age-related Change in Contractile Properties Connelly et al. 1999 Why is MVC lower? MUSCLE • Decrease in muscle size • Decrease in fibre size and perhaps number (80yrs ~ half the #) • Change in muscle composition, primarily Type IIb, IIa, I • Substitution of non‐contractile tissue MOTOR NEURON • Loss of MNs in ventral root • Reduction begins ~ 7th decade, by 9th decade loss is ~ 29% • Problem with counting: count what is there but may not be functioning 9 10/4/2023 MU Discharge rates Connelly et al. 1999 Dalton, Jakobi et al. 2010 Check-in • Physiological Change 10 10/4/2023 Is it just ‘gross’ movement? Video share from Neural Control of Movement Lab; Integrative Physiology Boulder Colorado; Feeney and RM Enoka Functional Movement • Physiology factors altering functional movement difficult to investigate • Isometric models of force • FS – magnitude of variability in force oscillations around a pre-established target force • Absolute quantification SD • Relative CV of force (ratio of SD to mean force) Young Male Old Male 11 10/4/2023 Age-related decline FS & Function • 36% of variance in pegboard time was explained by: • 1) Force steadiness (+) • 2) Maximal grip strength (-) Sex-specific differences in force steadiness Almuklass et al. (2016), Brown et al. (2010), Christou et al. (2004), Clark et al. (2005), Harwood et al. (2014), Grunte et al. (2010), Pereira et al. (2015), Tracy and Enoka (2002), Yoon et al. (2014). Jakobi JM, Haynes EMK, Smart RR. Is there sufficient evidence to explain the cause of sexually dimorphic behaviour in force steadiness? Appl Physiol Nutr Metab. 2018 Nov;43(11):1207‐1214. doi: 10.1139/apnm‐2018‐0196. PMID: 30189156. Smart, R. R., Baudry, S., Fedorov, A., Kuzyk, S. L., & Jakobi, J. M. (2018). Influence of biceps brachii tendon mechanical properties on elbow flexor force steadiness in young and old males. Scandinavian journal of medicine & science in sports, 28(3), 983‐991. 12 10/4/2023 Factors in Force Steadiness • Effective Neural Drive – Independent elements are filtered by pool of motoneurons – Common elements compose effective neural drive • Absolute and relative strength Hamilton et al. 2004; Farina & Negor 2015; Roos & Dingwell 2010 Limited data from humans on MN pool Jakobi JM, Haynes EMK, Smart RR. doi: 10.1139/apnm‐2018‐0196. PMID: 30189156 Brown RE, Edwards DL, Jakobi JM (2010doi: 10.1007/s00421‐010‐1600‐x From Animals Sex-specific Compensatory Counterbalance ? MN size and number • • Males bigger is bad but countered by greater number Females, smaller MN but too few in # to create big difference Check-in • Force Control 13 10/4/2023 APPLICATION Functional Dependence • Mobility declines with increasing age – GPS, Accelerometer, pedometer, questionnaire, decline in both community and resident mobility • Women at higher risk than men for functional dependence – – • Higher incidence of long term disability in women Mobility key for maintaining independence (Strauss et al.2003) Women higher prevalence of frailty Fitness -key in preventing dependence 60% reduced risk! Low High Low High 14 10/4/2023 Strength required to step up and rise from an armless chair Skelton et al 1998 Frailty a continuum • • Studies using the Frailty Index show females have higher FI scores than males. Females tolerate frailty better, e.g., lower mortality rate at any given FI score or age. (Gordon et al. 2017) Frailty Criteria 1. Weight loss 2. Exhaustion 3. Low PA 4. Muscle weakness 5. Slow walking speed Potential accumulation deficits < capacity 0 Early identification of signs/symptoms possible, but often missed 1 – 2 Criteria Frailty identified (too late) signs/symptoms > supports/capacity 3> 0 ‐ Robust 1‐2 ‐ Prefrail 3 > ‐ Frail Fried et al. 2001 (FI) threshold threshold Gordon, E. H., Peel, N. M., Samanta, M., Theou, O., Howlett, S. E., & Hubbard, R. E. (2017). Sex differences in frailty: a systematic review and meta-analysis. Experimental gerontology, 89, 30-40. Roland, K. P., Theou, O., Jakobi, J. M., Swan, L., & Jones, G. R. (2014). How do community physical and occupational therapists classify frailty? A pilot study. J Frailty Aging, 3, 247‐250. 15 10/4/2023 Resistance Training Click on most important component of training for pre-frail? Bray, N. W., Smart, R. R., Jakobi, J. M., & Jones, G. R. (2016). Exercise prescription to reverse frailty. Applied physiology, nutrition, and metabolism, 41(10), 1112‐1116. Exercise Intervention 16 10/4/2023 Intensity & Make it Real Exercise Outcomes Bray et al. J Frailty Aging. 2020;9(2):111‐117. doi: 10.14283/jfa.2020.13. Bray et al. J Frailty Aging. 2020;9(2):118‐121. doi: 10.14283/jfa.2020.15. 17 10/4/2023 Frailty Transition – It works = CON changed = EX changed = CON unchanged = EX unchanged A. Frailty Phenotype (FP) 0 1 2 3 4 Pre-Frail Non-Frail 5 Frail B. Clinical Frailty Scale (CFS) 1 2 Very Fit 3 Well 4 Managing Well 5 Vulnerable 6 6-9 Mildly Frail C. Gait Speed (GS; m/sec) 1 .7 5 1 .5 0 1 .2 5 Independent Bray et al. J Frailty Aging. 2020;9(2):111‐117. doi: 10.14283/jfa.2020.13. Bray et al. J Frailty Aging. 2020;9(2):118‐121. doi: 10.14283/jfa.2020.15. 1 .0 0 0 .7 5 0 .5 0 Transitioning Frail Frail Frailty Those that exercised = CON changed = EX changed = CON unchanged = EX unchanged A. Frailty Phenotype (FP) 0 1 2 3 Pre-Frail Non-Frail 4 5 Frail B. Clinical Frailty Scale (CFS) 1 Very Fit 2 Well 3 Managing Well 4 Vulnerable 5 6 6-9 Mildly Frail C. Gait Speed (GS; m/sec) 1 .7 5 Independent Independent 1 .5 0 1 .2 5 1 .0 0 Transitioning Frail Transitioning Frail 0 .7 5 Frail Frail 0 .5 0 Bray et al. J Frailty Aging. 2020;9(2):111‐117. doi: 10.14283/jfa.2020.13. Bray et al. J Frailty Aging. 2020;9(2):118‐121. doi: 10.14283/jfa.2020.15. 18 10/4/2023 Frailty-Those not exercising = CON changed = EX changed = CON unchanged = EX unchanged A. Frailty Phenotype (FP) 0 1 Non-Frail 2 3 4 5 Frail Pre-Frail B. Clinical Frailty Scale (CFS) 1 2 Very Fit Well 3 Managing Well 4 Vulnerable 5 6 6-9 Mildly Frail C. Gait Speed (GS; m/sec) 1 .7 5 1 .5 0 Independent Independent Bray et al. J Frailty Aging. 2020;9(2):111‐117. doi: 10.14283/jfa.2020.13. Bray et al. J Frailty Aging. 2020;9(2):118‐121. doi: 10.14283/jfa.2020.15. 1 .2 5 Transitioning Frail Transitioning Frail 1 .0 0 0 .7 5 0 .5 0 Frail Frail Check-in • Application 19 10/4/2023 Summary  Background   Canada is aging Sex and Gender Research is growing  Muscle strength is a factor – not sole factor  Force control  Exercise to reduce Frailty Thank you [email protected] Volunteers needed for research 20