Gastric emptying in hereditary transthyretin amyloidosis: the impact of autonomic neuropathy.
BACKGROUND
Gastrointestinal (GI) complications are common in hereditary transthyretin amyloidosis and an autonomic dysfunction has been considered to explain these symptoms. The aim of this study was to investigate the impact of autonomic neuropathy on gastric emptying in hereditary transthyretin amyloidosis and to relate these findings to nutritional status, GI symptoms, gender, and age at disease onset.


METHODS
Gastric emptying was evaluated with gastric emptying scintigraphy. Spectral analysis of the heart rate variability and cardiovascular responses after tilt test were used to assess the autonomic function. The nutritional status was evaluated with the modified body mass index (s-albumine × BMI).


RESULTS
Gastric retention was found in about one-third of the patients. A weak correlation was found between the scintigraphic gastric emptying rate and both the sympathetic (rs = -0.397, P < 0.001) and parasympathetic function (rs = -0.282, P = 0.002). The gastric emptying rate was slower in those with lower or both upper and lower GI symptoms compared with those without symptoms (median T(50) 123 vs 113 min, P = 0.042 and 192 vs 113 min, P = 0.003, respectively). Multiple logistic regression analysis showed that age of onset (OR 0.10, CI 0.02-0.52) and sympathetic dysfunction (OR 0.23, CI 0.10-0.51), but not gender (OR 0.76, CI 0.31-1.84) and parasympathetic dysfunction (OR 1.81, CI 0.72-4.56), contributed to gastric retention.


CONCLUSIONS
Gastric retention is common in hereditary transthyretin amyloidosis early after onset. Autonomic neuropathy only weakly correlates with gastric retention and therefore additional factors must be involved.
Departments of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden. jonas.wixner@medicin.umu.se
J
J
Wixner
P
P
Karling
A
A
Rydh
R
R
Hörnsten
U
U
Wiklund
I
I
Anan
O B
OB
Suhr
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D028227:Amyloid Neuropathies, Familial / Q000150:complications* / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001342:Autonomic Nervous System Diseases / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D005746:Gastric Emptying / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D055815:Young Adult