Heart rate variability during 6-min walk test in adults aged 40 years and older.

We evaluated age- and sex-dependent differences in heart rate variability (HRV) during the 6-min walk test (6MWT) in healthy adults. We also evaluated the intensity of the 6MWT based on HRV. 78 participants aged 40-49, 50-59, 60-69, and ≥ 70 years (42 females; 36 men) performed the 6MWT. Heart rate and HRV were monitored 1 min at rest and during the last 2-min of the test. The root mean square (RMSSD), instantaneous beat-to-beat variability (SD1), and long-term standard deviation (SD2) of RR intervals were calculated. The SD1 <3 ms at the end of the 6MWT was defined as high-intensity exercise. Despite the significantly higher peak values of heart rate observed for women, we did not find sex- and age-related differences in HRV during the 6MWT. The ROC curve identified percentage of maximum heart rate >67% as the best cut-point for prediction of high-intensity exercise with 94% of sensitivity and 65% of specificity (area under the curve=0.804). We may conclude that autonomic modulation of heart rate during exercise was not dependent of age and sex. The HRV assessment during walking enables a valid estimation of exercise intensity in adults. We may therefore suggest the use of 6MWT for assessing exercise capacity and for prescribing exercises in adults aged 40 yrs and older.

Immunoexpression of VEGFR-3, but not the immunoexpression of VEGF-C or lymphatic density, is correlated with metastasis in lower lip squamous cell carcinoma.

The purpose of this study was to evaluate the immunoexpression of vascular endothelial growth factor C (VEGF-C) and VEGF receptor 3 (VEGFR-3) and their correlation with intratumoural lymphatic density (ILD) and peritumoural lymphatic density (PLD) in metastatic and non-metastatic lower lip squamous cell carcinoma (LLSCC). Twenty-five LLSCC with regional nodal metastasis and 25 LLSCC without metastasis were selected. The percentages of VEGF-C and VEGFR-3 staining in each tumour core and at the deep invasive front were assessed. PLD and ILD were determined using anti-podoplanin antibody. Immunohistochemical findings were correlated with nodal metastasis, clinical staging, local recurrence, clinical outcome, and histological grade. Cytoplasmic immunoexpression of VEGFR-3 in the tumour core was associated with metastasis (P=0.009), patient death (P=0.008), and histological grade (P<0.005). PLD, ILD, and VEGF-C expression showed no significant associations with clinicopathological parameters (P>0.05). PLD and ILD were not significantly correlated with the immunoexpression of VEGF-C or VEGFR-3 (P>0.05). There was a significant positive correlation between PLD and ILD (P=0.004), and between cytoplasmic immunoreactivity of VEGF-C and VEGFR-3 (P=0.011). These results suggest an important role for VEGFR-3 in the progression of LLSCC, and highlight the possible influence of its expression on the prognosis of these tumours. ILD and PLD may not be associated with lymph node metastasis in LLSCC.