Consumption of hot protein-containing drink accelerates gastric emptying rate and is associated with higher hunger levels in older adults.

Meal temperature is known to affect gastric emptying and appetite. While protein intake is recommended for older age, gastric emptying is delayed with age, resulting in loss of appetite. This study aimed to investigate whether adjusting the temperature of protein-containing drinks could improve gastric emptying and appetite in older individuals. Twenty male and female participants aged 65 years and older underwent three one-day trials in random order. Participants visited the laboratory after a 10-hour fast and consumed 200 mL of protein-containing drink dissolved in 13C-sodium acetate at 4°C, 37°C, or 60°C in a 3-minute period. Then, participants sat in a chair for 90 minutes to measure gastric emptying rate by the 13C-sodium acetate breath test and subjective appetite by a visual analog scale. The results showed that 37°C and 60°C drinks had faster gastric emptying at 5 and 10 min after ingestion than did the 4°C drink (trial-time interaction, p = 0.014). Tmax-calc, an indicator of gastric emptying rate, tended to be faster for the 37°C and 60°C drinks than for the 4°C drink (49.7 ± 17.5 min vs. 44.1 ± 18.5 min vs. 45.3 ± 25.8 min for the 4°C, 37°C, and 60°C, respectively; p = 0.085). There were no significant differences in the change in hunger from baseline among the three different temperature drinks (p > 0.05). Only in the 60°C trial, a shorter gastric emptying time was associated with greater hunger (r=-0.554, p = 0.021). These findings suggest that hot protein-containing drinks may accelerate gastric emptying and contribute to rapid nutrient intake and increased appetite in older adults.

Factors explaining seasonal variation in energy intake: a review.

Maintaining a balance between energy intake and expenditure is crucial for overall health. There are seasonal variations in energy intake, with an increase during spring and winter as well as a decrease during summer. These variations are related to a combination of environmental factors, including changes in temperature and daylight hours; social factors, including events and holidays; and physiological factors, including changes in physical activity and emotions. Accordingly, this review aimed to summarize the environmental, social, and physiological factors that contribute to seasonal variations in energy intake. A review of the current literature revealed that changes in temperature and daylight hours may affect eating behavior by altering homeostatic responses and appetite-related hormones. Additionally, increased participation in events and frequency of eating out, especially during winter vacations, may contribute to increased energy intake. Notably, these findings may not be generalisable to all populations since environmental and social factors can vary significantly depending on the local climatic zones and cultural backgrounds. The findings of the present review indicate that seasonal climate, events, and associated hormonal changes should be taken into account in order to maintain adequate energy intake throughout the year.

Muscle stretching induces the mechanoreflex response in human arterial blood pressure.

The muscle mechanoreflex has been considered to make a small contribution to the cardiovascular response to exercise in healthy humans because no pressor response has been observed during stimulation of mechanosensitive receptors, such as static passive stretching, during many human studies. There is room for rethinking this consideration since the pressor response to upper limb exercise is greater than that to lower limb exercise. We examined whether static passive stretching of the forearm muscles causes a muscle mechanoreflex-induced pressor response in humans. Eighteen healthy men were recruited for this study. After a 15-min rest period in the supine position with a neutral (0°) wrist joint angle, all participants completed static passive stretching of the forearm for 60 s at four different intensities: minimal painful passive stretching (PPS), moderate-intensity passive stretching (MPS), low-intensity passive stretching (LPS), and no load (NL). During the procedure, beat-to-beat arterial blood pressure was measured using finger photoplethysmography. The force generated between the passively stretched hand and the experimenter's hands was recorded using a force transducer. Mean arterial pressure (MAP) during PPS and MPS significantly increased from baseline during the last 40 s (P < 0.05). MAP was significantly greater at 50 s and 60 s, depending on the intensity. MPS induced a greater peak response in MAP than lower intensities (P < 0.05). None of the subjects reported pain during the MPS and LPS trials. Static passive stimulation of the forearm is an effective method of isolating the muscle mechanoareflex-induced pressor response in humans.NEW & NOTEWORTHY The muscle mechanoreflex was considered to have a small contribution to cardiovascular regulation during exercise in healthy humans. In contrast, the results of this study indicate that static stretching of the forearm induces a pressor response in healthy humans and suggest that the mechanoreflex explicitly induces the pressor response during exercise in humans. The methods applied are useful for evaluating the pressor response to the mechanoreflex regardless of health, aging, and disease.

Effects of different temperatures of carbohydrate-protein-containing drinks on gastric emptying rate after exercise in healthy young men: randomized crossover trial.

BACKGROUND: The present study examined the effects of different temperatures of carbohydrate-protein-containing drinks after exercise on the subsequent gastric emptying rate in healthy young men. METHODS: Twelve healthy young men completed two, 1-day trials in random order. In both trials, the participants completed intermittent cycling exercise for 20 min, consisting of a 120% heart rate peak for 20 s, followed by 25 W for 40 s. Participants consumed 400 mL of carbohydrate-protein-containing drink (0.85 MJ) at 4 °C (EX + 4 °C) or 60 °C (EX + 60 °C) over a 5-min period after exercise. The participants sat on a chair for 2.5 h to measure their gastric emptying rate using the 13C-sodium acetate breath test. Subjective feelings of gastrointestinal discomfort and appetite were measured using a visual analog scale. Interstitial fluid glucose levels after drinking were measured using a continuous glucose-monitoring device. RESULTS: The percentage excretion of 13CO2 tended to be higher at EX + 60 °C than at EX + 4 °C from the start of the test until 30 min after drink ingestion (5.7 ± 0.5 vs. 6.5 ± 0.4%dose/h for the EX + 4 °C and EX + 60 °C trials, respectively; effect sizes [ES] = 0.277, p = 0.065). The time of maximum 13CO2 emissions per hour (Tmax-calc) and the time of half 13CO2 emissions per hour (T1/2) did not differ between trials. Subjective gastrointestinal discomfort was lower at EX + 60 °C compared to EX + 4 °C (ES = 0.328, p = 0.041). There were no significant differences in interstitial fluid glucose levels between the different temperatures of carbohydrate-protein-containing drinks after exercise (p = 0.698). CONCLUSIONS: Consumption of warm carbohydrate-protein-containing drinks after exercise may accelerate gastric emptying in the very early phase and may reduce gastric discomfort. TRIAL REGISTRATION: University Hospital Medical Information Network, UMIN000045626. Registered on June 10, 2021.

Musical instrumental reading affects middle cerebral blood flow and cognitive function.

Playing a musical instrument includes reading music scores, playing, and listening in parallel. It is unclear which of these activities are responsible for an increase in cerebral blood flow. We investigated the factors increasing middle cerebral artery velocity (MCAv) during musical performance, and examined whether playing and reading music affects cognitive function. Seventeen musicians played an instrument with reading music, played music from memory, and read music scores in a randomized order, for 10 min each. The MCAv was continuously recorded from 5 min before to 10 min after the performance. A Stroop test was performed before and after performance. The MCAv increased significantly with reading music, playing from memory, and reading music. Stroop test scores increased significantly after music reading. These findings suggest that both music reading and playing an instrument are involved in the increase in MCAv during music performance. Cognitive function was transiently improved by playing musical instruments.

Playing a musical instrument increases blood flow in the middle cerebral artery.

PURPOSE: Studies using functional magnetic resonance imaging and positron-emission tomography suggest that many regions of the brain are activated by such complex muscle activity. Although these studies demonstrated relative increases in blood flow in some brain regions with increased neural activity, whether or not the absolute value of cerebral blood flow increases has yet to be elucidated. It also remains unknown whether playing musical instruments affects cerebral blood flow. The aim of this study was to determine the impact of playing a musical instrument on blood flow velocity in the middle cerebral artery (MCAv) by using Doppler ultrasound to measure absolute values of arterial flow velocity. METHODS: Thirteen musicians performed three pieces of music with different levels of difficulty: play for the first time (FS), music in practice (PR) and already mastered (MS) on either piano or violin. MCAv was recorded continuously from 10 min before until 10 min after playing. Associations between the cerebral blood flow response and blood pressure and gas-exchange variables were examined. RESULTS: PR and MS significantly increased the MCAv. The blood pressure increased significantly in performances of all difficulty levels except for MS. There were no significant changes in exhaled gas variables during the performance. CONCLUSION: These findings suggest that playing a musical instrument increases MCAv, and that this change is influenced by the difficulty of the performance.

Effects of aging and exercise habits on blood flow profile of the ocular circulation.

PURPOSE: We examined the effects of aging and exercise habits on the ocular blood flow (OBF) and its profiles throughout the optic nerve head region and choroidal area. We hypothesized that exercise habits reduce the stiffness of vessels in the ocular circulation, which generally increases with aging. METHODS: Participants in a medical checkup program (698 males and 192 females aged 28 to 80 years) were categorized into 2 groups (with and without exercise habits) based on participant self-reporting and the definition of the Ministry of Health, Labor and Welfare of Japan (MHLW). OBF in the right eye was measured and analyzed using laser speckle flowgraphy. The blowout time (BOT), which is the time during which the blood flow is higher than half of the mean of the minimum and maximum signals during one heartbeat, was calculated as an index of the blood flow profile. BOT has been used as an indicator of the flexibility of blood vessels. RESULTS: BOT significantly decreased with aging. Neither the self-reported nor MHLW-based exercise habits significantly affected the ocular circulation. CONCLUSION: These results indicate that the stiffness of the ocular vessels increases with aging, and this cannot be prevented by exercise habits.

Impact of acute dynamic exercise on vascular stiffness in the retinal arteriole in healthy subjects.

Acute exercise can improve vascular stiffness in the conduit artery, but its effect on the retinal arterioles is unknown. The present study investigated the effects of acute dynamic exercise on retinal vascular stiffness. In experiment 1, we measured the cardio-ankle vascular index (CAVI), carotid artery intima-media thickness (carotid IMT), and retinal blood velocity by laser speckle flowgraphy in 28 healthy old and 28 young men (69 ± 3 and 23 ± 3 yr, respectively). Pulse waveform variables, which were used as an index of retinal vascular stiffness, were assessed by retinal blood flow velocity profile analysis. In experiment 2, 18 healthy old and 18 young men (69 ± 3 and 23 ± 3 yr, respectively) underwent assessment of pulse waveform variables after a 30-min bout of moderate cycling exercise at an intensity of 60% heart rate reserve. There was a significant difference in the baseline pulse waveform variables between the old and young groups. Pulse waveform variables in the retinal arteriole did not significantly change after acute dynamic exercise, whereas CAVI significantly decreased. These findings suggest that retinal vascular stiffness does not change by acute exercise. The effect of exercise on vascular stiffness in the retinal arterioles might be different from that in the conduit artery.NEW & NOTEWORTHY Acute dynamic exercise is well known to improve vascular stiffness in the conduit artery while its effect on the retinal arterioles has been unknown. This study showed that an acute dynamic exercise does not change vascular stiffness in the retinal arteriole in healthy humans. Different responses to acute dynamic exercise in vascular stiffness in retinal arterioles and conduit arteries are suggested.

Chewing increases postprandial diet-induced thermogenesis.

Slow eating, which involves chewing food slowly and thoroughly, is an effective strategy for controlling appetite in order to avoid being overweight or obese. Slow eating also has the effect of increasing postprandial energy expenditure (diet-induced thermogenesis). It is still unclear whether this is due to oral stimuli; that is, the duration of tasting food in the mouth and the duration of chewing. To investigate the effects of oral stimuli on diet-induced thermogenesis in 11 healthy normal weight males, we conducted a randomized crossover study comprising three trials: (1) drinking liquid food normally, (2) drinking liquid food after tasting, and (3) adding chewing while tasting. Oral stimuli (i.e., the duration of tasting liquid food in the mouth and the duration of chewing) significantly increased diet-induced thermogenesis after drinking liquid food. This result demonstrates that the increase in diet-induced thermogenesis is due to oral stimuli rather than the influence of the food bolus. Increased diet-induced thermogenesis induced by chewing and taste stimuli may help to prevent overweight and obesity.

Acute and Chronic Periocular Massage for Ocular Blood Flow and Vision: a Randomized Controlled Trial.

INTRODUCTION: The ocular blood flow (OBF) is responsible for supplying nutrition to the retina, which plays a fundamental role in visual function. Massage is expected to improve the blood flow and, consequently, vascular function. The aim of this study was to determine the short-term and long-term effects of periocular massage on OBF and visual acuity. METHODS: The OBF and visual acuity were measured in 40 healthy adults aged 20-30 years before and after massage, and also in control subjects. Three massage methods were used: applying periocular acupressure ("Chinese eye exercise": CE), using a facial massage roller (MR), and using an automated eye massager (AM). The OBF and visual acuity were first measured before and after applying each type of massage for 5 min. Eye massage was then applied for 5 min once daily over a 60-day period, while the control group received no massage. The same measurements were then performed again. RESULTS: Performing short-term periocular massage showed significant interactions in time and massage effects on visual acuity in CE and AM groups, and on OBF in AM group, while 60-day massage period exerted no significant effects. No significant relationship was found between OBF and visual acuity changes. CONCLUSIONS: These results suggest that short-term periocular massage with Chinese eye exercise and automated eye massager can improve OBF and visual acuity, although no causal relationship was supported.

Facial Blood Flow Responses to Dynamic Exercise.

We reported previously that a static handgrip exercise evoked regional differences in the facial blood flow. The present study examined whether regional differences in facial blood flow are also evoked during dynamic exercise. Facial blood flow was measured by laser speckle flowgraphy during 15 min of cycling exercise at heart rates of 120 bpm, 140 bpm and 160 bpm in 12 subjects. The facial vascular conductance index was calculated from the blood flow and mean arterial pressure. The regional blood flow and conductance index values were determined in the forehead, eyelid, nose, cheek, ear and lip. One-way ANOVA and Tukey's post-hoc test were used to examine effects of exercise intensity and target regions. The blood flow and conductance index in skin areas increased significantly with the exercise intensity. The blood flow and conductance index in the lip increased significantly at 120 bpm and 140 bpm compared to the control, while the values in the lip at 160 bpm did not change from the control values. These results suggest that the blood flow in facial skin areas, not in the lip, responds similarly to dynamic exercise, in contrast to the responses to static exercise.

Long-term safety and effectiveness of linagliptin as add-on therapy in Japanese patients with type 2 diabetes: final results of a 3-year post-marketing surveillance.

BACKGROUND: We investigated the long-term safety and effectiveness of linagliptin in Japanese type 2 diabetes (T2D) patients starting linagliptin add-on therapy in routine clinical practice. RESEARCH DESIGN AND METHODS: This 3-year prospective, observational, post-marketing surveillance (PMS) was conducted in Japanese patients starting linagliptin add-on therapy. The primary outcome was the incidence of adverse drug reactions (ADRs). The secondary outcome was the change from baseline in HbA1c. RESULTS: The safety analysis set comprised of 3,372 patients. Mean ± standard deviation (SD) age was 66.5 ± 12.4 years. Most patients (63.2%) received linagliptin in combination with another antidiabetic drug, most commonly a sulfonylurea (38.6%). The incidence of ADRs was 11.39%; the most common ADRs according to MedDRA preferred terms were diabetes mellitus (1.25%), hypertension (0.83%), and hypoglycemia (0.80%). In the effectiveness analysis set (n = 3,029), mean ± SD HbA1c was 7.76 ± 1.37% at baseline and 7.26 ± 1.19% at last observation; mean change from baseline to last observation was - 0.49 ± 1.33%; sustained reductions in HbA1c were observed. These results were consistent across patient subgroups. CONCLUSIONS: In this PMS, linagliptin add-on therapy for Japanese T2D patients had a safety profile consistent with its known profile and HbA1c reductions over 3 years were observed. CLINICALTRIALS.GOV: NCT01904383.

Long-Term Safety and Effectiveness of Linagliptin in Japanese Patients with Type 2 Diabetes and Renal Dysfunction: a Post-Marketing Surveillance Study.

INTRODUCTION: International clinical trials have shown that linagliptin significantly improves glycemic control and can be used at a single dose regardless of renal function in patients with type 2 diabetes (T2D). However, to date, no studies have evaluated the use of linagliptin in Japanese patients with T2D by renal function in routine clinical care. METHODS: This was a subgroup analysis of data from a prospective observational post-marketing surveillance (PMS) study of linagliptin conducted in Japan that evaluated the safety and effectiveness of linagliptin in routine clinical care for 3 years in Japanese patients with T2D. The subgroup analysis examined the patient population of this PMS study according to renal function using estimated glomerular filtration rate (eGFR) data. The incidence of linagliptin-related adverse events (adverse drug reactions [ADRs]) was the primary endpoint, and the change in glycated hemoglobin (HbA1c) from baseline to last observation was the secondary endpoint. RESULTS: Of the 2235 patients included in the safety analysis, eGFR was ≥ 90 mL/min/1.73 m2 (defined as group G1) in 16.9% (n = 377), ≥ 60 to < 90 mL/min/1.73 m2 (group G2) in 44.5% (n = 995), ≥ 30 to < 60 mL/min/1.73 m2 (group G3) in 21.7% (n = 486), ≥ 15 to < 30 mL/min/1.73 m2 (group G4) in 2.6% (n = 58) and < 15 mL/min/1.73 m2 (group G5) in 1.7% (n = 37). No eGFR data were available for 12.6% (n = 282) of patients. In these GFR groups, the incidence of ADRs with linagliptin was 6.9% in group G1, 11.1% in group G2, 13.8% in group G3, 15.5% in group G4 and 16.2% in group G5; the change in HbA1c from baseline to the last observation was - 1.11, - 0.64, - 0.35, - 0.46 and - 0.54% in the respective subgroups. CONCLUSIONS: Long-term linagliptin use showed sustained improvements in glycemic control with no new safety concerns regardless of renal function. TRIAL REGISTRATION: ClinicalTrials.gov (NCT01650259). FUNDING: This study was funded by Nippon Boehringer Ingelheim Co., Ltd. and Eli Lilly Japan K.K.

Altered metabolic regulation owing to gsp1 mutations encoding the nuclear small G protein in Saccharomyces cerevisiae.

Nutrient metabolism is regulated for adaptation to, for example, environmental alterations, cellular stress, cell cycle, and cellular ageing. This regulatory network consists of cross-talk between cytoplasmic organelles and the nucleus. The ras-like nuclear small G protein, Ran, functions in nuclear-cytosolic transport and regulatory signal transmission. In yeast, some genes involved in the Ran system in yeast are required for growth on glycerol medium. Growth deficiency, due to mutations in the GSP1 gene, which encodes Ran, is allele specific. Specifically in this study, the gsp1-1894 cells lost mitochondria, and could not grow on media containing glycerol, galactose or maltose. However, the gsp1-1894 cells grew better on a high salt medium (1 M NaCl) and had increased expression levels of GPD1-lacZ. Furthermore, disruption of the HOG1 gene suppressed their growth deficiency on glycerol medium. These findings suggest that altered activation of Hog1 in the gsp1-1894 cells resulted in the loss of mitochondria and inhibition of glycerol metabolism. Growth deficiency of the gsp1-1894 cells on galactose medium was further suppressed by high dosage of the SIP2 DNA, which encodes the cytosolic ß subunit of AMPK. This suggests that higher cytosolic activity of AMPK is required for the utilization of an alternative carbon source in gsp1-1894 cells.

Long-Term Safety and Effectiveness of Linagliptin in Japanese Patients with Type 2 Diabetes Mellitus: A 3-Year Post-Marketing Surveillance Study.

INTRODUCTION: Clinical trials of linagliptin in Japanese patients conducted to date have had limited observational periods; therefore, there is a need for additional longer-term real-world data. The aim of this study was to investigate the long-term safety and effectiveness of linagliptin in routine clinical practice. METHODS: This was a prospective, observational, post-marketing surveillance study conducted over 156 weeks in patients with type 2 diabetes mellitus who started linagliptin monotherapy. The primary endpoint was the incidence of adverse drug reactions (ADRs). The secondary endpoint was the change in glycated hemoglobin (HbA1c) from baseline to last available observation. Other effectiveness endpoints included the change in HbA1c and change in fasting plasma glucose (FPG) from baseline to week 26 and over the course of the treatment period. RESULTS: Overall, 2235 and 2054 patients were included in the safety and effectiveness analysis sets, respectively. Patients were mostly male (58.4%), and the mean age was 66.7 years. The incidence of ADRs was 10.7% (n = 240). The most frequent ADRs according to MedDRA preferred terms were diabetes mellitus (n = 35 patients, 1.6%), constipation (n = 21, 0.9%), diabetes mellitus inadequate control (n = 13, 0.6%) and hypertension (n = 13, 0.6%). The mean change in HbA1c from baseline to last observation was - 0.67% [standard deviation (SD) 1.27%, 95% confidence interval - 0.72, - 0.61]. At week 26, HbA1c and FPG showed mean ± SD changes from baseline of - 0.73 ± 1.20% and - 21.02 ± 44.33 mg/dL, respectively, that were sustained until week 156. CONCLUSIONS: In Japanese patients with type 2 diabetes mellitus, linagliptin produced sustained reductions in HbA1c and had a safety profile consistent with the established safety profile of linagliptin. TRIAL REGISTRATION: ClinicalTrials.gov (NCT01650259).

Cost-effectiveness Analysis of Empagliflozin in Japan Based on Results From the Asian subpopulation in the EMPA-REG OUTCOME Trial.

PURPOSE: The goal of this study was to assess the cost-effectiveness of empagliflozin in Japan based on the Asian subpopulation in the EMPA-REG OUTCOME trial. METHODS: The trial has shown a reduction in the risk for cardiovascular (CV) and renal events with empagliflozin in patients with type 2 diabetes mellitus and established CV disease. A cost-effectiveness analysis based on the overall population of the EMPA-REG OUTCOME trial was reported previously by using a lifetime discrete event simulation model. The same modeling frame was adapted to evaluate the cost-effectiveness of treatment with empagliflozin added to standard of care (SoC) compared with SoC alone in Japan. The time to relevant clinical events and the hazard ratios were derived from an Asian subpopulation in the EMPA-REG OUTCOME trial. The costs for each event were estimated from a Japanese medical claims database. Direct medical costs, life expectancy, and quality-adjusted life years (QALYs) were calculated from the public health care perspective. FINDINGS: Treatment with empagliflozin was estimated to increase life expectancy by 6.2 years and 2.7 QALYs, whereas total cost increased by 1,115,475 yen compared with treatment with SoC alone. The incremental cost-effectiveness ratio was 415,849 yen/QALY. In the sensitivity analysis, there was no case that was in excess of the reference value of the incremental cost-effectiveness ratio in the pilot introduction for price revision in Japan (ie, 5 million yen/QALY). IMPLICATIONS: Based on the Asian subpopulation in the EMPA-REG OUTCOME trial, our results suggest that empagliflozin added to SoC is highly cost-effective compared with SoC alone in Japan.

Regional differences in facial skin blood flow responses to thermal stimulation.

PURPOSE: The facial skin blood flow (SkBF) shows regional differences in the responses to a given stimulation. The facial SkBFs, especially in the eyelid and nose exhibit unique response to physiological and psychological stimuli, but the mechanisms inducing those regional differences remain unclear. To investigate whether the regional differences in the local control of vasomotion in facial vessels correspond to the regional differences in facial SkBF response, we monitored the relative change of facial SkBF to regional thermal stimulation. We hypothesized that heat stimulation dilates the cutaneous vessels in the eyelid, while cold stimulation constricts those in the nose, which was based on previous findings METHODS: A thermal stimulator was used to apply temperature increase (from 20 to 40 °C at 2 °C/min) and decrease (from 40 to 20 °C at 2°C/min) in a randomized order to the right eyelid, nose, right cheek, and forehead of 14 healthy young males. The facial SkBF was measured for 10 s using laser-speckle flowgraphy when temperatures of 20 °C, 30 °C, and 40 °C had been applied for 30 s in both trials. RESULTS: The SkBF in the eyelid did not change significantly during any thermal stimulation, and the nasal SkBF did not decrease significantly during cold stimulation. The SkBFs in the cheek and forehead increased significantly with the applied temperature. CONCLUSIONS: These findings indicate that a large regional variation exists in facial skin blood flow response to local heating or cooling and that the regional variation did not correspond to the unique SkBF responses in the previous studies.

Short- and long-term effects of using a facial massage roller on facial skin blood flow and vascular reactivity.

Massage rollers are commonly used for beauty care, but their effects on skin blood flow (SkBF) and vascular reactivity remain unclear. We hypothesized that the short-term usage of a massage roller increases the SkBF, while a long-term massage intervention improves vascular dilatation. We measured the facial SkBF change to 5 min massage roller to the right cheek in 12 subjects. We also assessed the effect of 5-week daily use of facial massage roller on the SkBF in the right cheek and the reactivity to local heat in 14 subjects. The short-term massage significantly increased facial SkBF solely in the right cheek for at least 10 min after the massage. The 5-week intervention significantly increased the vasodilatation response to the heat stimulation solely in the right cheek. These findings suggested that performing short-term facial massage with a roller increases SkBF, and long-term use improves the vascular dilatation response.

Aging decreases CO2 reactivity in the retinal artery, but not in the ocular choroidal vessels; a cross-sectional study.

BACKGROUND: The CO2 reactivity is often used to assess vascular function, but it is still unclear whether this reactivity is affected by aging. OBJECTIVE: To investigate the effects of aging on the CO2 reactivity in ocular and cerebral vessels, both of which are highly sensitive to hypercapnia, we compared the CO2 reactivity in the retinal artery (RA), retinal and choroidal vessels (RCV), optic nerve head (ONH), and middle cerebral artery (MCA) between young and middle-aged subjects. METHODS: We measured the CO2 reactivity in 14 young and 11 middle-aged males using laser-speckle flowgraphy during a 3-min inhalation of CO2-rich air. RESULTS: The CO2 reactivity in the RA and ONH were lower in the middle-aged group than in the young group, but no significant effect of age was observed in the RCV or MCA. The CO2 reactivity in the RA and ONH were correlated significantly with age, whereas those in the RCV or MCA were not. CONCLUSIONS: These findings suggest that there are regional differences in the effect of age on the CO2 reactivity among not only ocular and cerebral vessels, but also the retinal and choroidal vessels, even though these vessels are in neighboring areas.