The relation between serotonin levels and insufficient blood pressure decrease during night-time in hypertensive patients.
OBJECTIVE
The serotonin levels in thrombocytes are decreased in hypertensive patients. The aim of our study was to investigate the relationship between serotonin levels and insufficient nocturnal blood pressure (BP) decrease (non-dipper) in hypertensive patients.


METHODS
Fifty-six hypertensive patients and 27 healthy control subjects were included in the study. Of the hypertensive patients, 28 were classified as dippers and 28 as non-dippers based on nocturnal BP drops of >10 mmHg and <10 mmHg, respectively. Thrombocyte serotonin levels, serum uric acid, and C-reactive protein (CRP), and urinary albumin/creatinine ratios were analysed. Thrombocyte serotonin levels were measured using an enzyme immunoassay.


RESULTS
The thrombocyte serotonin level was 378.9 +/- 69.5 ng/10(9) platelet in the non-dipper group, 424.7 +/- 58.6 ng/10(9) platelet in the dipper group, and 518.1 +/- 35.9 ng/10(9) platelet in the control group. Serotonin levels in the non-dipper group were significantly lower than in the dipper group. Serotonin levels negatively correlated with blood pressure (r = -0.6, p<0.001). CRP concentration in the non-dipper group was higher than in the dipper (4.8 +/- 1.4 vs 3.6 +/- 1.6, p<0.01) and control (2.4 +/- 0.9, p<0.001) groups, and microalbuminuria was significantly higher in the non-dipper group compared with dipper (24.9 +/- 8.6 vs 13.4 +/- 8.8, p<0.001) and control (9.6 +/- 4.8, p<0.001) groups. Serotonin level was negatively correlated with microalbuminuria (p<0.001, r = -0.3), uric acid (p<0.01, r = -0.3), and CRP (p<0.01, r = -0.35).


CONCLUSIONS
In non-dipper hypertensive patients, thrombocyte serotonin levels were significantly lower than in dipper and control groups. Serotonin levels may be related to insufficient nocturnal blood pressure decrease in hypertensive patients.
Topsakal
Ramazan
R
Department of Cardiology, Erciyes University Medicine Faculty, Kayseri, Turkey. nihatkalay@hotmail.com
Kalay
Nihat
N
Gunturk
Ertugrul Emre
EE
Dogan
Ali
A
Inanc
Mehmet Tugrul
MT
Kaya
Mehmet Gungor
MG
Ergin
Ali
A
Yarlioglues
Mikail
M
D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001792:Blood Platelets / Q000378:metabolism; D001794:Blood Pressure / Q000502:physiology; D016022:Case-Control Studies; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000188:drug therapy / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012701:Serotonin / Q000097:blood*; D012893:Sleep Wake Disorders / Q000097:blood / Q000503:physiopathology
D000959:Antihypertensive Agents; D012701:Serotonin