Laser Doppler imaging of skin blood flow for assessing peripheral vascular impairment in hand-arm vibration syndrome.

The objective of this study was to evaluate the usefulness of laser Doppler imaging (LDPI) of the skin blood flow for assessing peripheral vascular impairment in the hand-arm vibration syndrome (HAVS). The subjects were 46 male patients with HAVS, aged 50 to 69 yr, and 31 healthy male volunteers of similar age as controls. A cold provocation test was carried out by immersing a subject's hand on his more severely affected side into cold water at a temperature of 10 degrees C for 10 min. Repeated image scanning of skin blood flow of the index, middle, and ring fingers was performed every 2 min before, during, and after the cold water immersion using a PMI-II laser Doppler perfusion imager. The mean blood perfusion values in the distal phalanx area of the fingers were calculated on each image. The patients suffering from vibration-induced white finger (VWF, n=20) demonstrated significantly lower skin blood perfusion at each interval of the test as compared with those without VWF (n=26) and the controls (p<0.01, ANOVA). The blood perfusions in the HAVS patients were associated with the severity of the symptoms as classified by the Stockholm Workshop scale for vascular staging. When a subject was considered to be positive if any of the tested fingers showing a decreased blood perfusion and/or a delayed recovery pattern, the sensitivity was 80.0%, and the specificity was 84.6% and 93.5% for patients without VWF and the controls, respectively. These results suggest that the LDPI technique could provide detailed and accurate information that may help detect the existence of impaired vascular regulation to cold exposure in the fingers of workers exposed to hand-transmitted vibration.

Preliminary study on the assessment of peripheral vascular response to cold provocation in workers exposed to hand-arm vibration using laser Doppler perfusion imager.

Measurements of changes in finger skin blood flow with laser Doppler perfusion imaging (LDPI) in response to cold provocation test (10 degrees C, 10 min) were performed in 12 men suffering from vibration induced white finger (VWF) and 13 exposed controls. The mean perfusion values in both groups reduced markedly as a result of immersion of the hand in cold water. In the controls, however, the mean value increased gradually until the end of the cold provocation, while that in the VWF subjects remained at the lowest level. After removal of the hand from the cold water, the skin blood perfusion in the controls recovered rapidly and nearly reached the baseline value. In the VWF subjects, it had a slight increase immediately following the cold immersion but no tendency to rise as the time span increased. Analysis of covariance controlling for possible confounders revealed that the VWF subjects had significantly lower perfusion values compared to the controls in the last several minutes of the cold provocation and the following recovery. These findings suggest that the LDPI technique enables visualizing and quantifying the peripheral vascular effects of cold water immersion on the finger skin blood perfusion and thus has the potential of providing more detailed and a&curate information that may help detect the peripheral circulatory impairment in the fingers of vibration-exposed workers.

Influence of Biomedical Factors on the Five Viscera Score (FVS) on Middle-Aged and Elderly Individuals: Application of Structural Equation Modeling.

The five viscera score (FVS) is a diagnostic scale for traditional Chinese medicine (TCM). The purposes of current study are to elucidate the characteristics of FVS obtained from middle-aged to elderly individuals and to investigate the validity of FVS using biological medical data of middle-aged and elderly individuals. Structural equation modeling (SEM) was used to conduct assessments between FVS and medical data. Eighty men and 99 women participated in this study, whose mean ages (SD) were 58 ± 7 years in both genders showing no significant difference. FVS of women was significantly higher than that of men in the spleen of the 50s (P = 0.019) and liver of the 60s age group (P = 0.030). By SEM, the following biomedical factors were found to influence viscera: gender, diastolic blood pressure, and HDL-C for the liver; GLU, GOT, and γ-GTP for the spleen; age, BMI, and HCRP for the lungs; and HbA1c and creatinine clearance for the kidneys. These results provide objective evidence that FVS can be used for TCM diagnosis in middle-aged and elderly individuals.

Validity of a diagnostic scale for acupuncture: application of the item response theory to the five viscera score.

In acupuncture therapy, diagnosis, acupoints, and stimulation for patients with the same illness are often inconsistent among between Traditional Chinese Medicine (TCM) practitioners. This is in part due to the paucity of evidence-based diagnostic methods in TCM. To solve this problem, establishment of validated diagnostic tool is inevitable. We first applied the Item Response Theory (IRT) model to the Five Viscera Score (FVS) to test its validity by evaluating the ability of the questionnaire items to identify an individual's latent traits. Next, the health-related QOL scale (SF-36), a suitable instrument for evaluating acupuncture therapy, was administered to evaluate whether the FVS can be used to make a health-related diagnosis. All 20 items of the FVS had adequate item discrimination, and 13 items had high item discrimination power. Measurement accuracy was suited for application in a range of individuals, from healthy to symptomatic. When the FVS and SF-36 were administered to other subjects, a part of which overlap with the first subjects, we found an association between the two scales, and the same findings were obtained when symptomatic and asymptomatic subjects were compared regardless of age and sex. In conclusion, the FVS may be effective in clinical diagnosis.

Morphologic classification of nailfold capillary microscopy in workers exposed to hand-arm vibration.

The aim of this study was to investigate the association between the morphologic classification of nailfold capillary microscopy and the clinical and demographic findings in workers exposed to hand-arm vibration. The subjects were 44 male forestry workers (average age; 51.9 ± 14.8 yr). The nailfold capillaries (NC) and the mean blood flow velocity were measured on the middle finger of the dominant side by a peripheral capillary observer. The analyses were made using 39 subjects after excluding five subjects who received medication for hypertension. The observed NC were classified into 5 types according to Kusumoto's classification: Type I, n=5; Type II, n=15; Type III, n=8; Type IV, n=5; and Type V, n=6. After excluding the subjects in the Type V, we divided the subjects into two groups: Type I/II group, n=20; and Type III/IV group, n=13. In the Type III/IV group, the operating year of handheld vibrating tools was relatively longer, the mean blood flow velocity was significantly slower, and the body mass index was relatively higher as compared to the Type I/II group. These results suggested that the nailfold capillary microscopy may reflect the effect of the vibration exposure.