Figure 49.1 shows that men develop Ledderhose Disease earlier than women. The average age of onset found for men is 41.4 (median = 43) and for women 47.5 (median = 50).

Having a family history means that close relatives have or had Dupuytren and/or Ledderhose Disease. 528 patients reported having family history, 214 stated that they don’t know (‘unknown’) and 251 had no family history or were not aware of any relatives with DD or LD. Below we are counting ‘unknown’ and ‘no’ as having no (known) family history. Patients with family history have an average age of onset of 43.3 and without family history an average age of onset of 46. Note that these are not prevalence data, i.e. having a family history might well mean that the chances to develop LD (or DD) are much higher, but the average age of onset is only a few years earlier.

78.2 % of the LD patients report suffering also from Dupuytren Disease. Overall, concurrent DD does not seem to have strong effect: the average age of onset for patients also suffering from DD is 45.4, even a little but not significantly later than the total average of 44.6. A strong difference appears when it is additionally taken into account which disease started first: patients with concurrent DD who had Ledderhose first report an onset of LD at 38, and if DD came first, the onset of LD was at 49.4. That difference is to some extent ‘natural’ because those with an early onset of Ledderhose Disease are all in the group ‘Ledderhose first’, thus lowering the average age of onset. If patients with an onset of LD <30 are excluded from the analysis, the average age of onset for the group with ‘Ledderhose first’ jumps to 46.8, while for ‘Dupuytren first’, the age of onset for LD increases only slightly to 51.

Smoking is affecting the onset of Ledderhose Disease as shown in Fig. 49.2. For comparison also included in Fig. 49.2 are results for not smoking women without family history thus eliminating influences that might cause an earlier onset.

We found an average age of onset of Ledderhose Disease for smokers 40.2 (median = 40), for nonsmokers 45.0 (median = 48) and for nonsmoking women without family history 49.6 (median = 52).

For alcohol consumption, we observed no significant effect on the age of onset of LD. The average was 44.7 if drinking more than 2 glasses of wine/pints of beer per day, 44.2 if drinking less than 2 glasses of wine/pints of beer per day and 45.2 if not drinking at all. Our survey did not inquire about specifically heavy alcohol consumption.