Incidence rates of surgically treated idiopathic carpal tunnel syndrome in blue- and white-collar workers and housewives in Tuscany, Italy.

OBJECTIVES: Rates of surgically treated carpal tunnel syndrome (CTS) among blue- and white-collar workers and housewives in the general population were compared. METHODS: Surgically treated cases of idiopathic CTS were investigated among 25-59-year-old residents of Tuscany, Italy, during 1997-2000, based on obligatory discharge records from all Italian public/private hospitals, archived according to residence on Tuscany's regional database. Population data were extracted from the 2001 census. RESULTS: After excluding repeat admissions, 8801 eligible cases were identified. Age-standardised rates (per 100 000 person-years) of surgical CTS were: "blue-collar women", 367.8; "white-collar women", 88.1; "housewives", 334.5; "blue-collar men", 73.5; and "white-collar men", 15.3. Compared with reference categories (same-sex white-collar workers): female blue-collar workers experienced a 4.2-fold higher standardised rate; housewives, a 3.8-fold excess; and male blue-collar workers, a 4.8-fold excess (all p<0.001). Male and female blue-collar workers showed approximately three to sevenfold higher age-specific rates compared to their white-collar counterparts (all p<0.001). Housewives' rates were similar to those of blue-collar female workers up to 40-44 years of age, after which they were significantly lower (p<0.002). At all ages, housewives' rates were much higher (p<0.001) than those of white-collar women. CONCLUSIONS: Surgically treated CTS was three to seven times more common (depending on age/gender) in blue-collar than in white-collar workers, which is difficult to explain by differences in body weight or other individual factors. Thus, occupational risk factors seem relevant throughout working life. The high rates for full-time housewives suggest that domestic chores should be investigated as a possible risk factor for CTS.

[Progress of studies promoted by the MODS collaborative group]. / Fase di avanzamento degli studi promossi dal gruppo collaborativo MODS.

In industrialised countries, carpal tunnel syndrome (CTS) is considered an epidemic work-related disease. We have set up the MODS (Malattie Occupazionali Da Sovraccarico biomeccanico, biomechanical overload-related occupational diseases) collaborative group, formed by epidemiologists, ergonomists and occupational physicians to investigate CTS in Italy, applying the methods that epidemiologists commonly use to understand epidemics. Several studies are already ongoing. Two different descriptive studies based on current hospitalisation data are in the reporting phase. A pilot case-control multicentre study (260 cases and 520 controls in 13 centres) is in the final phase of data collection. A longitudinal study on a cohort of 3000 subjects exposed to different risk factors has reached the third year of follow-up. Moreover, a surveillance system has been set up to cover selected districts of the Emilia Romagna region. These studies will generate new information about the prevalence and incidence of CTS in Italy, along with identification of regional, high-risk job titles and work sectors, and the relative influence of non-occupational factors.

[Electromyography of those exposed to vibration]. / Elettromiografia negli esposti a vibrazioni.

Electrophysiological findings in the median and ulnar nerves of a group of ten workers who operate hand-held vibrating power tools are described. Motor conduction velocities, motor latencies and amplitude of evoked compound muscle action potentials were measured. We have observed statistically significant changes in the distal latencies and in the amplitude of evoked compound muscle action potentials of median nerves in all the subjects examined, whereas the motor conduction velocities were normal in both median and ulnar nerve. These findings are compatible with functional changes without a clinically manifest neuropathy and they are suggestive of a compression damage such as carpal tunnel syndrome: the possible pathogenic mechanism of these damages are discussed. It's necessary to emphasize the importance of further studies in order to estimate the type and entity of the exposure to vibrations to show a cause-effect relationship.