Blood Levels of Caffeine May Help Diagnose Parkinson’s Study finds decreased metabolites in early disease, regardless of caffeine consumption

Unrelated to total caffeine consumption or disease severity, serum levels of caffeine and nine of its downstream metabolites were significantly lower in patients with early Parkinson's, Shinji Saiki, MD, PhD, of Juntendo University School of Medicine in Tokyo, and colleagues reported online in Neurology. There were no significant genetic variations in the enzymes metabolizing caffeine between patients and controls. One reason why early Parkinson's patients had decreased caffeine levels may be related to intestinal absorption, the authors suggested. Gastrointestinal problems like constipation can affect up to 80% of Parkinson's patients, sometimes preceding symptom onset by years, and a recent analysis showed that fecal microbial flora is altered in patients with Parkinson's. "Although constipation and fecal bacterial change are predominantly attributed to large intestine function, caffeine absorption mainly occurs in the small intestine, where bacterial overgrowth in Parkinson's is associated with levodopa . Another explanation might be anti-parkinsonian agents. "There is an elephant in the room: almost all patients with Parkinson's were receiving treatment," wrote Munoz and Fujioka. "The authors address this issue by finding no association between levels of caffeine metabolites and levodopa equivalent doses, but it is obvious that the validity of the study hangs on this point." "If a future study were to demonstrate similar decreases in caffeine in untreated patients with Parkinson's, or persons with prodromal signs of Parkinson's including REM behavior disorder, many of whom would be expected to develop Parkinson's, the implications of the current study would take enormous importance," they continued. This could lead to an easy test for early diagnosis or point to a basic mechanism of Parkinson's pathogenesis. https://www.medpagetoday.com/neurology/parkinsonsdisease/70281?xid=nl_mpt_DHE_2018-01-04&eun=g721819d0r&pop=0&ba=1&pos=0&utm_source=Sailthru&utm_medium=email&utm_campaign=Daily%20Headlines%202018-01-04&utm_term=Daily%20Headlines%20-%20Active%20User%20-%20180%20days