We appreciate the comments received following the publication of our case report on late-onset acquired generalized lipodystrophy with muscle involvement in Actas Dermo-Sifiliográficas,1 and would like to add the following clarifications.

Subclinical hypothyroidism affects up to 20% of women aged over 65 years, and appears to have little influence on muscle mass or quality in this subgroup of patients.2 There have, however, been isolated reports of polymyositis in patients with hypothyroidism.3 In such cases, there tend to be signs and symptoms of neuromuscular involvement, with biopsy showing inflammatory muscle infiltrates or signs of atrophy.3 Furthermore, Duyff et al.4 reported increased creatine kinase (CK) levels in a group of hypothyroid patients (n=24), but observed no association with thyroid-stimulating hormone (TSH) or free thyroxine (T4) levels or with muscle signs and symptoms. The authors also reported that these patients may show both neuropathic (24%) and myopathic (10%) electrodiagnostic changes. Our patient was diagnosed with subclinical hypothyroidism in August 2008. The condition was successfully controlled with oral levothyroxine 25mg/d, with normalization of TSH levels. Regarding the possible relationship between the increased CK levels in our patient and the use of fibrates to treat hypertriglyceridemia, it should be noted that these levels had been elevated since 2005, when treatment was started with gemfibrozil (replaced by fenofibrate in 2008). Rhabdomyolysis due to fibrates typically presents between 36hours and 6 months after ingestion of the drug, is most often caused by gemfibrozil, and can result in acute renal failure.5 Fortunately, there are few such cases, but slight elevations in CK are not uncommon in patients on gemfibrozil, especially when it is used in combination with statin therapy.

We cannot, therefore, rule out the possibility that fibrate therapy might have contributed to our patient's persistently elevated CK levels. However, numerous factors suggest that these were more likely to have been related to her general condition, namely, the absence of signs or symptoms of muscle involvement or clinical weakness, the persistent elevation in CK levels despite the change in fibrate therapy and its temporary suspension, and finally the detection of myopathic changes by electromyography.