Non-pharmacological interventions for vascular health and the role of the endothelium.

The most common non-pharmacological intervention for both peripheral and cerebral vascular health is regular physical activity (e.g., exercise training), which improves function across a range of exercise intensities and modalities. Numerous non-exercising approaches have also been suggested to improved vascular function, including repeated ischemic preconditioning (IPC); heat therapy such as hot water bathing and sauna; and pneumatic compression. Chronic adaptive responses have been observed across a number of these approaches, yet the precise mechanisms that underlie these effects in humans are not fully understood. Acute increases in blood flow and circulating signalling factors that induce responses in endothelial function are likely to be key moderators driving these adaptations. While the impact on circulating factors and environmental mechanisms for adaptation may vary between approaches, in essence, they all centre around acutely elevating blood flow throughout the circulation and stimulating improved endothelium-dependent vascular function and ultimately vascular health. Here, we review our current understanding of the mechanisms driving endothelial adaptation to repeated exposure to elevated blood flow, and the interplay between this response and changes in circulating factors. In addition, we will consider the limitations in our current knowledge base and how these may be best addressed through the selection of more physiologically relevant experimental models and research. Ultimately, improving our understanding of the unique impact that non-pharmacological interventions have on the vasculature will allow us to develop superior strategies to tackle declining vascular function across the lifespan, prevent avoidable vascular-related disease, and alleviate dependency on drug-based interventions.

Cool-Water Immersion Reduces Postexercise Quadriceps Femoris Muscle Perfusion More Than Cold-Water Immersion.

PURPOSE: The muscle perfusion response to postexercise cold-water immersion (CWI) is not well understood. We examined the effects of graded postexercise CWI upon global and regional quadriceps femoris muscle perfusion using positron emission tomography and [15O]H2O. METHODS: Using a matched-group design, 30 healthy men performed cycle ergometer exercise at 70% V̇O2peak to a core body temperature of 38°C, followed by either 10 min of CWI at 8°C, 22°C, or seated rest (control). Quadriceps muscle perfusion; thigh and calf cutaneous vascular conductance; intestinal, muscle, and local skin temperatures; thermal comfort; mean arterial pressure; and heart rate were assessed at preexercise, postexercise, and after CWI. RESULTS: Global quadriceps perfusion was reduced beyond the predefined minimal clinically relevant threshold (0.75 mL per 100 g·min-1) in 22°C water versus control (difference (95% confidence interval (CI)), -2.5 (-3.9 to -1.1) mL per 100 g·min-1). Clinically relevant decreases in muscle perfusion were observed in the rectus femoris (-2.0 (-3.0 to -1.0) mL per 100 g·min-1) and vastus lateralis (-3.5 (-4.9 to -2.0) mL per 100 g·min-1) in 8°C water, and in the vastus lateralis (-3.3 (-4.8 to -1.9) mL per 100 g·min-1) in 22°C water versus control. The mean effects for vastus intermedius and vastus medialis perfusion were not clinically relevant. Clinically relevant decreases in thigh and calf cutaneous vascular conductance were observed in both cooling conditions. CONCLUSIONS: The present findings revealed that less noxious CWI (22°C) promoted clinically relevant postexercise decreases in global quadriceps muscle perfusion, whereas noxious cooling (8°C) elicited no effect.

The effects of exercise training in the cold on cerebral blood flow and cerebrovascular function in young healthy individuals.

Exercise elicits acute increases in cerebral blood flow velocity (CBFv) and provokes long-term beneficial effects on CBFv, thereby reducing cerebrovascular risk. Acute exposure to a cold stimulus also increases CBFv. We compared the impact of exercise training in cold and thermoneutral environments on CFBv, cerebrovascular function and peripheral endothelial function. Twenty-one (16 males, 22 ± 5 years) individuals were randomly allocated to either a cold (5 °C) or thermoneutral (15 °C) exercise intervention. Exercise consisted of 50-min cycling at 70% heart rate max, three times per week for eight weeks. Transcranial Doppler was used to determine pre and post intervention CBFv, dynamic cerebral autoregulation (dCA) and cerebrovascular reactivity (CVRCO2). Conduit endothelial function, microvascular function and cardiorespiratory fitness were also assessed. Cardiorespiratory fitness improved (2.91 ml.min.kg-1, 95%CI 0.49, 5.3; P = 0.02), regardless of exercise setting. Neither intervention had an impact on CBFv, CVRCO2, FMD or microvascular function (P > 0.05). There was a significant interaction between time and condition for dCA normalised gain with evidence of a decrease by 0.192%cm.s-1.%mmHg-1 (95%CI -0.318, -0.065) following training in the cold and increase (0.129%cm.s-1.%mmHg-1, 95%CI 0.011, 0.248) following training in the thermoneutral environment (P = 0.001). This was also evident for dCA phase with evidence of an increase by 0.072 rad (95%CI -0.007, 0.152) following training in the cold and decrease by 0.065 (95%CI -0.144, 0.014) radians following training in the thermoneutral environment (P = 0.02). Both training interventions improved fitness but CBFv, CVRCO2 and peripheral endothelial function were unaltered. Exercise training in the cold improved dCA whereas thermoneutral negated dCA.

A Systematic Review and Meta-Analysis Examining Whether Changing Ovarian Sex Steroid Hormone Levels Influence Cerebrovascular Function.

Sex differences in cerebrovascular disease rates indicate a possible role for ovarian sex steroid hormones in cerebrovascular function. To synthesise and identify knowledge gaps, a systematic review and meta-analysis was conducted to assess how ovarian sex steroid hormone changes across the lifespan affect cerebrovascular function in women. Three databases (EMBASE, MEDLINE and Web of Science) were systematically searched for studies on adult cerebrovascular function and ovarian sex steroid hormones. Forty-five studies met pre-defined inclusion criteria. Studied hormone groups included hormone replacement therapy (HRT; n = 17), pregnancy (n = 12), menstrual cycle (n = 7), menopause (n = 5), oral contraception (n = 2), and ovarian hyperstimulation (n = 2). Outcome measures included pulsatility index (PI), cerebral blood flow/velocity (CBF), resistance index (RI), cerebral autoregulation, and cerebrovascular reactivity. Meta-analysis was carried out on HRT studies. PI significantly decreased [-0.05, 95% CI: (-0.10, -0.01); p = 0.01] in post-menopausal women undergoing HRT compared to post-menopausal women who were not, though there was considerable heterogeneity (I 2 = 96.8%). No effects of HRT were seen in CBF (p = 0.24) or RI (p = 0.77). This review indicates that HRT improves PI in post-menopausal women. However, there remains insufficient evidence to determine how changing ovarian sex steroid hormone levels affects cerebrovascular function in women during other hormonal phases (e.g., pregnancy, oral contraception).

Corrigendum: Cerebral Hemodynamic and Neurotrophic Factor Responses Are Dependent on the Type of Exercise.

[This corrects the article DOI: 10.3389/fphys.2020.609935.].

Ergogenic effect of pre-exercise chicken broth ingestion on a high-intensity cycling time-trial.

BACKGROUND: chicken meat extract is a popular functional food in Asia. It is rich in the bioactive compounds carnosine and anserine, two histidine-containing dipeptides (HCD). Studies suggest that acute pre-exercise ingestion of chicken extracts has important applications towards exercise performance and fatigue control, but the evidence is equivocal. This study aimed to evaluate the ergogenic potential of the pre-exercise ingestion of a homemade chicken broth (CB) vs a placebo soup on a short-lasting, high-intensity cycling exercise. METHODS: fourteen men participated in this double-blind, placebo-controlled, crossover intervention study. Subjects ingested either CB, thereby receiving 46.4 mg/kg body weight of HCD, or a placebo soup (similar in taste without HCD) 40 min before an 8 min cycling time trial (TT) was performed. Venous blood samples were collected at arrival (fasted), before exercise and at 5 min recovery. Plasma HCD were measured with UPLC-MS/MS and glutathione (in red blood cells) was measured through HPLC. Capillary blood samples were collected at different timepoints before and after exercise. RESULTS: a significant improvement (p = 0.033; 5.2%) of the 8 min TT mean power was observed after CB supplementation compared to placebo. Post-exercise plasma carnosine (p <  0.05) and anserine (p <  0.001) was significantly increased after CB supplementation and not following placebo. No significant effect of CB supplementation was observed either on blood glutathione levels, nor on capillary blood analysis. CONCLUSIONS: oral CB supplementation improved the 8 min TT performance albeit it did not affect the acid-base balance or oxidative status parameters. Further research should unravel the potential role and mechanisms of HCD, present in CB, in this ergogenic approach.

Repeated sprint cycling performance is not enhanced by ischaemic preconditioning or muscle heating strategies.

Introduction: Both ischaemic preconditioning (IPC) and muscle heat maintenance can be effective in enhancing repeated-sprint performance (RSA) when applied individually, acting mechanisms of these interventions, however, likely differ. It is unclear if, when combined, these interventions could further improve RSA. Methods: Eleven trained cyclists undertook experimental test sessions, whereby IPC (4 × 5-min at 220 mmHg) and SHAM (4 × 5-min at 20 mmHg) were each performed on two separate visits, each combined with either passive muscle heating or thermoneutral insulation prior to an "all-out" repeated-sprint task (10 × 6-s sprints with 24-s recovery). Primary outcome measures were peak and average power output (W), whist secondary measures were muscular activation and muscular oxygenation, measured via Electromyography (EMG) and Near-infrared spectroscopy (NIRS), respectively. Results: IPC did not enhance peak [6 (-14-26)W; P = 0.62] or average [12 (-7-31)W; P = 0.28] power output versus SHAM. Additionally, no performance benefits were observed when increasing muscle temperature in combination with IPC [5 (-14-19) watts; P = 0.67], or in isolation to IPC [9 (-9-28)W; P = 0.4] versus SHAM. No changes in EMG or microvascular changes were present (P > 0.05, respectively) between conditions. Conclusion: Overall, neither IPC, muscle heating, or a combination of both enhances RSA cycling performance in trained individuals.

Distinguishing factors that influence attendance and behaviour change in family-based treatment of childhood obesity: A qualitative study.

OBJECTIVES: For the effective treatment of childhood obesity, intervention attendance and behaviour change at home are both important. The purpose of this study was to qualitatively explore influences on attendance and behaviour change during a family-based intervention to treat childhood obesity in the North West of England (Getting Our Active Lifestyles Started (GOALS)). DESIGN: Focus groups with children and parents/carers as part of a broader mixed-methods evaluation. METHODS: Eighteen focus groups were conducted with children (n = 39, 19 boys) and parents/carers (n = 34, 5 male) to explore their experiences of GOALS after 6 weeks of attendance (/18 weeks). Data were analysed thematically to identify influences on attendance and behaviour change. RESULTS: Initial attendance came about through targeted referral (from health care professionals and letters in school) and was influenced by motivations for a brighter future. Once at GOALS, it was the fun, non-judgemental healthy lifestyle approach that encouraged continued attendance. Factors that facilitated behaviour change included participatory learning as a family, being accountable and gradual realistic goal setting, whilst challenges focussed on fears about the intervention ending and a lack of support from non-attending significant others. CONCLUSIONS: Factors that influence attendance and behaviour change are distinct and may be important at different stages of the family's change process. Practitioners are encouraged to tailor strategies to support both attendance and behaviour change, with a focus on whole family participation within and outside the intervention.

Cerebral Hemodynamic and Neurotrophic Factor Responses Are Dependent on the Type of Exercise.

This study examined acute cerebral hemodynamic and circulating neurotrophic factor responses to moderate intensity continuous exercise (MICT), guideline-based high intensity interval exercise (HIIT), and sprint interval exercise (SIT). We hypothesized that the pattern of middle cerebral artery velocity (MCAv) response would differ between interval and continuous exercise, with SIT inducing the smallest increase from rest, while increases in neurotrophic factors would be intensity-dependent. In a randomized crossover design, 24 healthy adults (nine females) performed three exercise protocols: (i) MICT (30 min), (ii) HIIT (4 × 4 min at 85% HRmax), and (iii) SIT (4 × 30 s supramaximal). MCAv significantly increased from rest across MICT (Δ13.1 ± 8.5 cm⋅s-1, p < 0.001) and all bouts of HIIT (Δ15.2 ± 9.8 cm⋅s-1, p < 0.001), but only for the initial bout of SIT (Δ17.3 ± 11.6 cm⋅s-1, p < 0.001). Immediately following each interval bout, MCAv increased (i.e., rebounded) for the SIT (9-14% above rest, p ≤ 0.04), but not HIIT protocol. SIT alone induced significant elevations from rest to end-exercise in vascular endothelial growth factor (VEGF; Δ28 ± 36%, p = 0.017) and brain-derived neurotrophic factor (BDNF, Δ149% ± 162%, p < 0.001) and there were greater increases in lactate than in either other protocol (>5-fold greater in SIT, p < 0.001), alongside a small significant reduction at the end of active recovery in insulin-like growth factor 1 (IGF-1, Δ22 ± 21%, p = 0.002). In conclusion, while the nature of the response may differ, both guideline-based and sprint-based interval exercise have the potential to induce significant changes in factors linked to improved cerebrovascular and brain health.

Historical reviews of the assessment of human cardiovascular function: interrogation and understanding of the control of skin blood flow.

Several techniques exist for the determination of skin blood flow that have historically been used in the investigation of thermoregulatory control of skin blood flow, and more recently, in clinical assessments or as an index of global vascular function. Skin blood flow measurement techniques differ in their methodology and their strengths and limitations. To examine the historical development of techniques for assessing skin blood flow by describing the origin, basic principles, and important aspects of each procedure and to provide recommendations for best practise. Venous occlusion plethysmography was one of the earliest techniques to intermittently index a limb's skin blood flow under conditions in which local muscle blood flow does not change. The introduction of laser Doppler flowmetry provided a method that continuously records an index of skin blood flow (red cell flux) (albeit from a relatively small skin area) that requires normalisation due to high site-to-site variability. The subsequent development of laser Doppler and laser speckle imaging techniques allows the mapping of skin blood flow from larger surface areas and the visualisation of capillary filling from the dermal plexus in two dimensions. The use of iontophoresis or intradermal microdialysis in conjunction with laser Doppler methods allows for the local delivery of pharmacological agents to interrogate the local and neural control of skin blood flow. The recent development of optical coherence tomography promises further advances in assessment of the skin circulation via three-dimensional imaging of the skin microvasculature for quantification of vessel diameter and vessel recruitment.

Relationship Between Endothelial Function and the Eliciting Shear Stress Stimulus in Women: Changes Across the Lifespan Differ to Men.

Background Premenopausal women have a lower incidence of cardiovascular disease, which may partly be due to a protective effect of estrogen on endothelial function. Animal studies suggest that estrogen may also improve the relationship between shear rate ( SR ) and endothelial function. We aimed to explore the relationship between endothelial function (ie, flow-mediated dilation [ FMD ]) and SR (ie, SR area under the curve [ SRAUC ]) in women versus men, and between pre- versus postmenopausal women. Methods and Results Brachial artery FMD and SRAUC were measured in accordance with expert-consensus guidelines in 932 healthy participants who were stratified into young adults (18-40 years, 389 men, 144 women) and older adults (>40 years, 260 men, 139 women). Second, we compared premenopausal (n=173) and postmenopausal women (n=110). There was evidence of a weak correlation between SRAUC and FMD in all groups but older men, although there was variation in strength of outcomes. Further exploration using interaction terms (age-sex× SRAUC ) in linear regression revealed differential relationships with FMD (young women versus young men [ß=-5.8-4, P=0.017] and older women [ß=-5.9-4, P=0.049]). The correlation between SRAUC and FMD in premenopausal women ( r2=0.097) was not statistically different from that in postmenopausal women ( r2=0.025; Fisher P=0.30). Subgroup analysis using stringent inclusion criteria for health markers (n=505) confirmed a stronger FMD - SRAUC correlation in young women compared with young men and older women. Conclusions Evidence for a stronger relationship between endothelial function and the eliciting SR stimulus is present in young women compared with men. Estrogen may contribute to this finding, but larger healthy cohorts are required for conclusive outcomes.

Conduit Artery Diameter During Exercise Is Enhanced After Local, but Not Remote, Ischemic Preconditioning.

Introduction: The ability of ischemic preconditioning (IPC) to enhance exercise capacity may be mediated through altering exercise-induced blood flow and/or vascular function. This study investigated the hypothesis that (local) IPC enhances exercise-induced blood flow responses and prevents decreases in vascular function following exercise. Methods: Eighteen healthy, recreationally trained, male participants (mean ±SD: age 32 ± 8 years; BMI 24.2 ± 2.3; blood pressure 122 ± 10/72 ± 8 mmHg; resting HR 58 ± 9 beats min-1) received IPC (220 mmHg; 4 × 5-min bilateral arms), REMOTE IPC (220 mmHg; 4 × 5-min bilateral legs), or SHAM (20 mmHg; 4 × 5-min bilateral arms) in a counterbalanced order prior to 30-min of submaximal (25% maximal voluntary contraction) unilateral rhythmic handgrip exercise. Brachial artery diameter and blood flow were assessed every 5-min throughout the 30-min submaximal exercise using high resolution ultrasonography. Pre- and post-exercise vascular function was measured using flow-mediated dilation (FMD). Results: IPC resulted in enlarged brachial artery diameter during exercise [0.016 cm (0.003-0.03 cm), P = 0.015] compared to REMOTE IPC, but blood flow during exercise was similar between conditions (P > 0.05). Blood flow (l/min) increased throughout exercise (time: P < 0.005), but there was no main effect of condition (P = 0.29) or condition ∗ time interaction (P = 0.83). Post-exercise FMD was similar between conditions (P > 0.05). Conclusion: Our data show that local (but not remote) IPC, performed as a strategy prior to exercise, enhanced exercise-induced conduit artery diameter dilation, but these changes do not translate into increased blood flow during exercise nor impact post-exercise vascular function.

Identifying Frail-Related Biomarkers among Community-Dwelling Older Adults in Japan: A Research Example from the Japanese Gerontological Evaluation Study.

We examined correlating clinical biomarkers for the physical aspect of frailty among community-dwelling older adults in Japan, using Japanese Gerontological Evaluation Study (JAGES). We used information from the JAGES participants (N = 3,128) who also participated in the community health screening in 2010. We grouped participants' response to the Study of Osteoporotic Fracture (SOF) Frailty Index into robust (=0), intermediate frail (=1), and frail (=2+) ones to indicate physical aspect of frailty. Independent of sex and age, results from multinomial logistic regression showed above normal albumin and below normal HDL and haemoglobin levels were positively associated with intermediate frail (RRR = 1.99, 95% CI = 1.22-3.23; RRR = 1.36, 95% CI = 1.33-1.39; RRR = 1.36, 95% CI = 1.23-1.51, resp.) and frail cases (RRR = 2.27, 95% CI = 1.91-2.70; RRR = 1.59, 95% CI = 1.51-1.68; RRR = 1.40, 95% CI = 1.28-1.52, resp.). Limited to women, above normal Hb1Ac level was similarly associated with intermediate frail and frail cases (RRR = 1.18, 95% CI = 1.02, 1.38; RRR = 2.56, 95% CI = 2.23-2.95, resp.). Use of relevant clinical biomarkers can help in assessment of older adults' physical aspect of frailty.

Localised cutaneous microvascular adaptation to exercise training in humans.

PURPOSE: Exercise training induces adaptation in conduit and resistance arteries in humans, partly as a consequence of repeated elevation in blood flow and shear stress. The stimuli associated with intrinsic cutaneous microvascular adaptation to exercise training have been less comprehensively studied. METHODS: We studied 14 subjects who completed 8-weeks cycle ergometer training, with partial cuff inflation on one forearm to unilaterally attenuate cutaneous blood flow responses during each exercise-training bout. Before and after training, bilateral forearm skin microvascular dilation was determined using cutaneous vascular conductance (CVC: skin flux/blood pressure) responses to gradual localised heater disk stimulation performed at rest (33, 40, 42 and 44 °C). RESULTS: Cycle exercise induced significant increases in forearm cutaneous flux and temperature, which were attenuated in the cuffed arm (2-way ANOVA interaction-effect; P < 0.01). We found that forearm CVC at 42 and 44 °C was significantly lower in the uncuffed arm following 8-weeks of cycle training (P < 0.01), whereas no changes were apparent in the contralateral cuffed arm (P = 0.77, interaction-effect P = 0.01). CONCLUSIONS: Lower limb exercise training in healthy young men leads to lower CVC-responses to a local heating stimulus, an adaptation mediated, at least partly, by a mechanism related to episodic increases in skin blood flow and/or skin temperature.

Do acute effects of exercise on vascular function predict adaptation to training?

PURPOSE: No previous study has explored the importance of exercise-induced changes in vascular function to prolonged adaptations. Therefore, the purpose was to explore the within-subject relationship between the acute post-exercise change in brachial artery endothelial function (flow-mediated dilation, FMD) and the change in resting FMD after a 2-week exercise training in healthy volunteers. METHODS: Twenty one healthy, young men (24 ± 5 years) underwent assessment of brachial artery FMD using high-resolution ultrasound before and after 30-min of moderate-intensity cycle exercise (80% maximal heart rate). Subsequently, subjects performed five 30-min cycle exercise bouts at 80% maximal heart rate across a 2-week period, followed by repeat assessment of resting brachial FMD post-training. RESULTS: Correcting for changes in diameter and shear, FMD did not change after the initial exercise bout (P = 0.26). However, a significant correlation was found between post-exercise changes in FMD and adaptation in resting FMD after training (r = 0.634, P = 0.002), where an acute decrease in post-exercise FMD resulted in a decrease in baseline FMD after 2 weeks and vice versa. We also found a positive correlation between antegrade shear rate during exercise and change in FMD% after acute exercise and after exercise training (r = 0.529 and 0.475, both P < 0.05). CONCLUSION: Our findings suggest that acute post-exercise changes in vascular function are related to changes in resting FMD after a 2-week endurance exercise training period in healthy men, an effect that may be related to exercise-induced increases in antegrade shear rate. This provides further insight into the relevance of acute changes in shear and FMD for subsequent adaptation.

Is There an Optimal Ischemic-Preconditioning Dose to Improve Cycling Performance?

INTRODUCTION: Ischemic preconditioning (IPC) may enhance endurance performance. No previous study has directly compared distinct IPC protocols for optimal benefit. PURPOSE: To determine whether a specific IPC protocol (ie, number of cycles, amount of muscle tissue, and local vs remote occlusion) elicits greater performance outcomes. METHODS: Twelve cyclists performed 5 different IPC protocols 30 min before a blinded 375-kJ cycling time trial (TT) in a laboratory. Responses to traditional IPC (4 × 5-min legs) were compared with those to 8 × 5-min legs and sham (dose cycles), 4 × 5-min unilateral legs (dose tissue), and 4 × 5-min arms (remote). Rating of perceived exertion and blood lactate were recorded at each 25% TT completion. Power (W), heart rate (beats/min), and oxygen uptake ([Formula: see text]) (mL · kg-1 · min-1) were measured continuously throughout TTs. Magnitude-based-inference statistics were employed to compare variable differences to the minimal practically important difference. RESULTS: Traditional IPC was associated with a 17-s (0, 34) faster TT time than sham. Applying more dose cycles (8 × 5 min) had no impact on performance. Traditional IPC was associated with likely trivial higher blood lactate and possibly beneficial lower [Formula: see text] responses vs sham. Unilateral IPC was associated with 18-s (-11, 48) slower performance than bilateral (dose tissue). TT times after remote and local IPC were not different (0 [-16, 16] s). CONCLUSION: The traditional 4 × 5-min (local or remote) IPC stimulus resulted in the fastest TT time compared with sham; there was no benefit of applying a greater number of cycles or employing unilateral IPC.

Monitoring Athlete Training Loads: Consensus Statement.

Monitoring the load placed on athletes in both training and competition has become a very hot topic in sport science. Both scientists and coaches routinely monitor training loads using multidisciplinary approaches, and the pursuit of the best methodologies to capture and interpret data has produced an exponential increase in empirical and applied research. Indeed, the field has developed with such speed in recent years that it has given rise to industries aimed at developing new and novel paradigms to allow us to precisely quantify the internal and external loads placed on athletes and to help protect them from injury and ill health. In February 2016, a conference on "Monitoring Athlete Training Loads-The Hows and the Whys" was convened in Doha, Qatar, which brought together experts from around the world to share their applied research and contemporary practices in this rapidly growing field and also to investigate where it may branch to in the future. This consensus statement brings together the key findings and recommendations from this conference in a shared conceptual framework for use by coaches, sport-science and -medicine staff, and other related professionals who have an interest in monitoring athlete training loads and serves to provide an outline on what athlete-load monitoring is and how it is being applied in research and practice, why load monitoring is important and what the underlying rationale and prospective goals of monitoring are, and where athlete-load monitoring is heading in the future.

Can sleep disturbance influence changes in mental health status? Longitudinal research evidence from ageing studies in England and Japan.

BACKGROUND: Little is known about the role of sleep disturbance in relation to changes in depressive states. We used data obtained from the participants aged 65 and over in the English Longitudinal Study of Ageing (ELSA, waves four and five, N = 3108) and the Japan Gerontological Evaluation Study (JAGES, 2010 and 2013 sweeps, N = 7527) to examine whether sleep disturbance is longitudinally associated with older adults' patterns of depressive states. METHODS: We created four patterns of depressive states (non-case, recovered, onset, repeatedly depressive) by combining responses to the measures (scoring four or more on seven items from the Center for Epidemiological Studies Depression Scale for the ELSA participants and scoring five or more for the Geriatric Depression Scale-15 for the JAGES participants) obtained at the baseline and follow-up. Sleep disturbance was assessed through responses to three questions on sleep problems. Age, sex, partnership status, household equivalised income, alcohol and cigarette use, and physical function were treated as confounders in this study. Additionally, information on sleep medication was available in JAGES and was included in the statistical models. RESULTS: More ELSA participants were non-depressive cases and reported no sleep disturbances compared with the JAGES participants. Findings from multinomial logistic regression analysis showed that more sleep disturbance was associated with the onset group in ELSA (RRR = 2.37, 95% CI = 1.44-3.90) and JAGES (RRR = 2.41, 95% CI = 1.79-3.25) as well as the recovery (RRR = 3.42, 95% CI = 1.98-5.90, RRR = 2.71, 95% CI = 1.95-3.75) and repeatedly depressed group (RRR = 7.24, 95% CI = 3.91-13.40, RRR = 5.16, 95% CI = 3.82-6.98). CONCLUSIONS: Findings suggest that the association between sleep disturbance and depression in older adults is complex.