Follow-up of a large population of asymptomatic/oligosymptomatic hyperckemic subjects

Abstract

Six years before the present study we performed a retrospective study of 114 subjects presenting with asymptomatic / oligosymptomatic hyperckemia (raised creatine kinase blood levels), a diagnosis being made in 21 of them. We now present the results of a long-term follow-up in 55 of the still undiagnosed 93 individuals. Most of them have remained asymptomatic and did not develop specific neuromuscular disorders. One subject became frankly symptomatic manifesting limb-girdle weakness. A diagnosis of dystrophinopathy carrier and one of possible type I SMA carrier were indirectly made in another two subjects. Almost all subjects still have hyperckemia, though the mean creatine kinase (CK) value is lower than before. CK levels have become normal in 12 subjects. Two died of neoplasia, and six developed non-neuromuscular disorders. We noted no follow-up differences in terms of CK modifications between subjects with pathological EMG and/or muscle biopsy findings and those with normal findings at first examination.

Hypertension risk in idiopathic hyperCKemia

“…None of these participants had any clinical evidence of tissue damage after up to 20 years of follow-up. Therefore, the probability that subjects with myopathies participated in our study is very low [4,10,20].…”

“…The preponderance of men in idiopathic hyperCKemia series [4,10,20,21] is unexplained. Higher tissue CK activity [2] and greater physical activity in men may contribute to this phenomenon.…”

“…Patients who met the following criteria were included: 1) persistently elevated sCK activity (with an adjusted upper limit for black people), which remained unexplained after thorough clinical and laboratory examination [4,10,20,21,28]; 2) no abnormalities found with neurological examination; 3) no history of episodes of malignant hyperthermia or rhabdomyolysis; 4) no family history of neuromuscular disease; 5) no use of drugs or substances known to cause high sCK activity at the time of the diagnosis, including cholesterol-lowering drugs [3,4,10,16,20]; 6) no recent muscle trauma; 7) no hypokalemia, and no endocrinological, infectious, malignant or haematological disease.…”

“…Patients with persistently raised serum creatine kinase (sCK) activity in whom neuromuscular diseases have been excluded are labeled as having idiopathic hyperCKemia,and are usually reassured and discharged [4,10,20,21]. However, these patients may be at risk for systemic arterial hypertension.…”

Asymptomatic hyperCKemia during a two-year monitoring period: A case report and literature overview

“…Despite the fact that in some cases CPK concentration levels may be extremely high, long-term follow-up has no clinical impact since the prognosis of this condition is benign (11,12). A follow-up study identified persistent hyperCKemia in 78% of asymptomatic patients after a 6-year period as well as an association between CK normalization and a normal muscle biopsy in 22% (12).…”