Sex-dependent impact of a short rest after lunch on hemodynamics as assessed by Doppler sonography.

PURPOSE: Taking a short rest after lunch suppresses increases in blood flow to the digestive organs and maintains blood flow to the brain in the afternoon, possibly providing beneficial effects in preventing post-prandial drowsiness. The present study investigated sex-dependent influences on changes in hemodynamics produced by taking a short rest after lunch. METHODS: Subjects comprised 20 healthy young adults (10 men, 10 women; mean age 21 ± 1 years). Doppler sonography was performed to measure blood flow in the superior mesenteric artery (SMA) and common carotid artery (CCA) before and after lunch every hour on each day, with and without a 15-min rest with eyes closed after lunch. Blood pressure and heart rate (HR) were also measured. RESULTS: For both men and women, peak systolic velocity (PSV) in the SMA was suppressed by taking a rest. PSV in the CCA in men was increased at 0.5 h after lunch in the resting condition but was decreased in the non-resting condition (median 109%, interquartile range [IQR] 102-120% vs. median 98%, IQR 90-107%; P = 0.037). No such differences were observed in women. Although post-prandial increases in HR were observed in women, a similar increase was only found for men in the resting condition. CONCLUSION: An increase in CCA blood flow was observed only in men. The present study suggests that a short rest after lunch could better promote the maintenance of blood flow to the brain in men than in women.

Close relationships between neck and upper-back stiffness and transverse cervical artery flow velocity.

PURPOSE: Neck and upper-back stiffness is encountered in daily life, with symptoms appearing as dullness or aches predominantly in the trapezius muscle (TM). Our previous study demonstrated that TM hardness as measured with a muscle hardness meter correlates well with transverse cervical artery (TCA) flow supplying the TM. Muscle hardness meters, however, cannot measure hardness in the TM alone. Meanwhile, recent advances in ultrasound elastography have enabled the evaluation of localized hardness in targeted tissues. The present study, therefore, aimed to clarify the relationship between TM hardness as measured by elastography and TCA hemodynamics as measured on Doppler sonography, with reference to daily symptoms of upper-back stiffness. METHODS: The study population comprised 66 healthy young adults (32 males, 34 females; mean age, 21 ± 1 years). Relationships were evaluated between TM hardness as a negative correlate of strain ratio from elastography and TCA hemodynamics on Doppler sonography. Hemodynamics in the TCA were evaluated according to the frequency of neck and upper-back stiffness. RESULTS: TM strain ratio correlated with peak systolic velocity (PSV) in the TCA (r = 0.273, p = 0.036), particularly in symptomatic subjects (r = 0.417, p = 0.022). PSV in the TCA decreased with increasing frequency of daily symptoms (p = 0.045). CONCLUSION: TCA hemodynamics correlated with muscle hardness when evaluating localized TM hardness. This relationship and low PSV in the TCA were evident in symptomatic subjects. These results suggest that PSV in the TCA is associated with neck and upper-back stiffness.

Possible effects of short rest after lunch on hemodynamics in the afternoon.

PURPOSE: Drowsiness is often experienced in the afternoon after lunch. Decreases in blood flow to the brain secondary to increases in blood flow to the digestive organs after food intake could represent an underlying cause. As various beneficial effects of short rests on mental activities have been reported, the present study investigated hemodynamics using Doppler sonography of the common carotid artery (CCA) and superior mesenteric artery (SMA) after lunch, comparing resting and non-resting cases. METHODS: Subjects comprised 24 healthy young adults (10 men, 14 women; mean age 22 ± 1 years). Sonography was performed to measure blood flow before and after lunch on each day, with and without a 15-min lying rest with eyes closed after lunch in each subject. RESULTS: The timing of the peak velocity-time integral in the SMA in resting cases was delayed to 1.5 h after lunch compared to 0.5 h in non-resting cases. Although end-diastolic velocity in the CCA decreased after lunch, this decrease was suppressed in resting cases compared to non-resting cases even 4.5 h after lunch (median 96%, interquartile range [IQR] 83-102% vs. median 87%, IQR 77-92%; P = 0.037). Mean velocity (MV) in the CCA maintained unchanged after lunch in resting cases (P = 0.318), whereas non-resting cases showed decreased MV after lunch (P < 0.001). CONCLUSION: These findings suggest that a short lying rest with eyes closed suppresses increases in blood flow to the digestive organ and maintains blood flow to the brain after lunch. These hemodynamic changes might help explain the benefits of afternoon rests.

Sonographically Measured Adipose Tissue Thickness Correlates with Laboratory Test Abnormalities Reflecting Metabolic State in Elderly Women.

Background: Accumulation of adipose tissue progresses to metabolic diseases. Sonography is a convenient modality for measuring the thickness of adipose tissue. The present study aimed to clarify the site of adipose tissue thickness that correlated best with laboratory test values reflecting metabolic abnormalities. Methods: Subjects comprised 37 elderly women with metabolic diseases or an almost healthy state (median age, 71 years; interquartile range, 62-78 years). Abdominal visceral adipose tissue (VAT), subcutaneous adipose tissue, peritoneal adipose tissue, perirenal adipose tissue, and epicardial adipose tissue (EAT) thicknesses were measured. Correlations were evaluated between laboratory test values and these adipose tissue thicknesses. Results: VAT thickness measured at the level of the umbilicus correlated positively with values of triglycerides (TGs) (r = 0.593, P = 0.0009) and hemoglobin A1c (r = 0.490, P = 0.0081) and negatively with the value of high-density lipoprotein cholesterol (r = -0.521, P = 0.0045), even after adjusting for body mass index. Significant positive correlations were also found between EAT thickness and TGs (r = 0.542, P = 0.0029). Conclusions: Among the adipose tissue thicknesses measured at several sites by sonography, VAT thickness correlated most closely with laboratory test values representing metabolic abnormalities in elderly women.

Relationship between trapezius muscle hardness and transverse cervical artery flow in association with neck and upper-back stiffness.

Neck and upper-back stiffness is a common discomfort encountered occasionally in daily life among otherwise healthy subjects. The pathogenesis of this condition could be attributable to increased tension in muscles such as the trapezius muscle (TM). The transverse cervical artery (TCA) is one of the feeding arteries for the TM, and TCA flow is reportedly related to symptoms of neck and upper-back stiffness. This study quantitatively investigated relationships between TM hardness and TCA hemodynamics as evaluated on Doppler sonography. Questionnaires regarding neck and upper-back stiffness, muscle hardness measurements obtained using a muscle hardness meter and examinations of TCA hemodynamics using Doppler sonography were performed on 55 healthy young adults (25 males, 30 females; mean age, 22 ± 2 years). Subjects displaying neck and upper-back stiffness actually exhibited high muscle hardness (median, 14.0; interquartile range (IQR), 12.9-18.0) compared to those without the symptom (median, 12.0; IQR, 9.9-14.0; p = .002). Peak systolic velocity in the TCA on Doppler sonography was lower in subjects with the symptom (median, 65.1 cm/s; IQR 59.6-72.5 cm/s) than in those without the symptom (median, 72.5 cm/s; IQR 66.5-84.2 cm/s; p = .012). Resistive index in the TCA was high (r2  = .605, p = .014) with increasing TM hardness, particularly among male subjects with the symptom. The present study suggests that high resistance and low blood flow velocity in the TCA could be closely associated with the underlying pathogenesis of neck and upper-back stiffness.

Sonographic detection of physiological lower leg oedema in the late afternoon in healthy young women.

Lower leg oedema occurs physiologically in the evening after daytime activity. Various oedema-related sonographic findings have recently been reported, but this physiological oedema has not been evaluated quantitatively using imaging examinations. The present study investigated whether sonography could detect physiological lower leg oedema, comparing measured values between the morning and late afternoon. Diameters of leg veins were also measured as a possible source of leg oedema. Subjects comprised 55 healthy young women (mean age, 21 ± 1 years). Oedema-related findings such as papillary dermis thickness, subcutaneous adipose tissue thickness and echogenicity (as estimated in grey-scale using image analysis software) increased in the late afternoon when compared with those in the morning (1.4 [1.1-1.7] mm vs. 1.4 [1.1-1.8] mm, p < .01; 7.3 [6.0-8.1] mm vs. 7.3 [6.1-8.3] mm, p < .05; and 37.3 [31.5-39.4] vs. 39.8 [35.7-44.1], p < .01, respectively). Diameters of leg veins such as the great saphenous vein, small saphenous vein and dorsal vein of the foot were all reduced towards late afternoon (p < .01 each). Sonography quantitatively and precisely detected physical changes associated with physiological lower leg oedema after daytime activity in healthy young women.

Influence of resting before sonographic examination on Doppler measurements of renal blood flow.

Renal artery stenosis (RAS) is the most common cause of secondary hypertension, via increases in plasma renin-angiotensin-aldosterone levels. Renal artery stenosis is diagnosed from blood examinations such as renin activity and from imaging examinations such as sonography. Patients are required to lie on the bed for 30 min before and during phlebotomy, since plasma renin activity is easily altered by posture. However, no such pre-examination rest is required for sonography. The present study therefore investigated the possible influence of resting before examination on Doppler parameters used for the diagnosis of RAS. Subjects comprised 55 healthy young adults (24 males, 31 females; mean age, 22 ± 1 years). Sonographic measurements were made shortly after subjects entered the examination room and again after 30 min of rest lying on a bed. Median peak systolic velocity in the renal artery was significantly decreased after rest (106 cm/s, interquartile range (IQR) 96-121 cm/s) compared with before rest (120 cm/s, IQR 107-135 cm/s; p < .001). Median acceleration time in the intra-renal segmental artery was also significantly shorter after rest (49 ms, IQR 38-54 ms) compared to before rest (50 ms, IQR 38-59 ms; p = .039). The present results suggest that serious consideration should be given regarding whether pre-examination resting is needed to accurately interpret Doppler measurements of renal blood flow when diagnosing RAS from sonography.