Normative data for neuromuscular assessment of the hand-arm vibration syndrome and its retrospective applications in Korean male workers

Vinculin Identified as a Potential Biomarker in Hand-Arm Vibration Syndrome Based on iTRAQ and LC-MS/MS-Based Proteomic Analysis

Local vibration can induce vascular injuries, one example is the hand-arm vibration syndrome (HAVS) caused by hand-transmitted vibration (HTV). Little is known about the molecular mechanism of HAVS-induced vascular injuries. Herein, the iTRAQ (isobaric tags for relative and absolute quantitation) followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) proteomics approach was applied to conduct the quantitative proteomic analysis of plasma from specimens with HTV exposure or HAVS diagnosis. Overall, 726 proteins were identified in iTRAQ. 37 proteins upregulated and 43 downregulated in HAVS. Moreover, 37 upregulated and 40 downregulated when comparing severe HAVS and mild HAVS. Among them, Vinculin (VCL) was found to be downregulated in the whole process of HAVS. The concentration of vinculin was further verified by ELISA, and the results suggested that the proteomics data was reliable. Bioinformative analyses were used, and those proteins mainly engaged in specific biological processes like binding, focal adhesion, and integrins. The potential of vinculin application in HAVS diagnosis was validated by the receiver operating characteristic curve.

Acute physiological and functional effects of repetitive shocks on the hand-arm system - a pilot study on healthy subjects

PURPOSE

Exposure to hand-transmitted shocks is a widespread phenomenon at the workplace. Separate risk assessments for shocks do not exist in current international hand-arm vibration regulations, leading to a potential underestimation of associated health risks.

METHODS

In a pilot study approach, N = 8 healthy males were exposed to sets of 3×5 minutes of repetitive shocks and 1×5 minutes of random vibration, controlled at a weighted vibration total value of 10 m/s² respectively. Baseline and post-exposure measurements of vibration perception thresholds, finger skin temperature, maximal grip / pinch force and the Purdue Pegboard test were conducted. Muscle activity was monitored continuously by surface electromyography.

RESULTS

Shock exposures evoked a temporary increase of vibration perception thresholds with high examination frequencies. A decrease of skin temperature was hinted for 1 s^-1 and 20 s^-1 shocks. Electromyographical findings indicated an additional load on two forearm muscles during shock transmission. Maximum grip force and manual dexterity were not affected, pinch force only partially reduced after the exposures.

CONCLUSION

Physiological effects from shock exposure conform to those described for hand-arm vibration exposure in principle, although some divergence can be hypothesized. Randomized designs are required to conclusively assess the need of occupational health concepts specifically for hand-transmitted shocks.

Hand-grip strength as a screening tool for sarcopenia in males with decompensated cirrhosis

BACKGROUND

Skeletal muscle index (SMI), the gold standard for sarcopenia, cannot measure muscle strength and requires specialized software and training. Hand-grip strength (HGS) measurement is cheap, requires minimal training and directly reflects muscle strength. We assessed the performance of HGS as a screening tool for sarcopenia in male patients with decompensated cirrhosis (DC).

METHODS

Consecutive male DC patients (n=155) were enrolled. Baseline liver functions, etiologic work-up and anthropometric measurements were done. SMI was determined from computed tomography (CT) images at L3 level using ImageJ software. Sarcopenia was diagnosed using SMI cut-off <42 cm²/m² as suggested by the Indian National Association for Study of the Liver. HGS was assessed using a hand-grip dynamometer. Diagnostic performance of HGS for discriminating sarcopenia was described using receiver operating characteristic (ROC) analysis. Diagnostic performance of different HGS cut-offs was assessed. Findings were internally validated using bootstrapping.

RESULTS

Mean HGS and SMI were 25.73 ± 5.94 kg and 47.72 ± 8.71 cm²/m², respectively. HGS showed modest correlation with SMI (tau: 0.31, p <0.001). Sarcopenia was seen in 41 (26.5%) patients. Age and HGS were independent predictors of sarcopenia on multivariate analysis. Area under the ROC curve (AUROC) of HGS for detecting sarcopenia was 0.73 (p<0.001). Optimal cut-off for using HGS as a screening tool was ≤31 kg (sensitivity: 37/41 [90.2%]; specificity: 29/114 [25.4%]; positive predictive value [PPV] : 37/122 [30.3%]; and negative predictive value [NPV]: 29/33 [87.9%]).

CONCLUSION

Prevalence of sarcopenia in Indian male patients with DC is 26.5%. HGS is an independent predictor of sarcopenia and can be used as a screening tool to stratify the need for confirmatory CT-based assessment of sarcopenia.

Dose-response relationship between hand-arm vibration exposure and vibrotactile thresholds among roadworkers

BACKGROUND

Testing of vibration perception threshold (VPT) at the fingertips as a quantitative measure of tactile sensitivity is a commonly used tool in diagnosing hand-arm vibration syndrome. There is limited research on dose-response relationships between hand-arm vibration (HAV) exposure and VPT on an individual level.

AIMS

Assess possible dose-response relationships on an individual level between HAV exposure and VPT at the fingertips.

METHODS

We assessed average daily vibration exposure (m/s²A8) and cumulative lifetime HAV exposure for 104 participants from different departments in a road maintenance company based on vibration measurements and questionnaires. VPT was measured based on the technical method described in ISO 13091-1:2005 using octave frequencies 8-500 Hz. We investigated associations using linear regression models with significance level p≤0.05.

RESULTS

The participants were either exposed to rock drills (n=33), impact wrenches (n=52) or none of these tools (n=19). Exposure to rock drills and impact wrenches was associated with elevated VPT for all seven test frequencies in the second and fifth fingers of both hands. A dose-response with the daily exposure measure m/s²(A8) was found based on 1.2 m/s²(A8) for impact wrenches, and 5.4 m/s²(A8) for rock drills. A stronger association was found with the cumulative exposure for rock drills compared with impact wrenches, and for the second finger compared with the fifth finger.

CONCLUSIONS

HAV exposure was associated with elevated VPT, also at exposure levels below the common exposure action value of 2.5 m/s²(A8). Lowering the HAV exposure can contribute to prevent increasing VPTs in these workers.