Monocyte count is an underlying marker of lacunar subtype of hypertensive small vessel disease.

BACKGROUND In the hypertensive small vessel disease (HSVD), it remains unclear why some patients develop lacunar infarcts (LIs) whilst others develop deep intracerebral hemorrhages (dICHs). Inflammation might be related to LI, and leukocyte and monocyte counts are regarded as an inflammatory marker of ischemic stroke. OBJECTIVE We investigated the relationship between leukocyte and monocyte counts determined in the first 24 h after stroke onset in HSVD patients. METHODS We prospectively studied 236 patients with first acute stroke because of HSVD (129 LI and 107 dICH). We analyzed demographic data, vascular risk factors, and white blood cell count subtypes obtained in the first 24 h after stroke. RESULTS The multivariate analysis showed that LI subtype of HSVD was correlated with hyperlipidemia (P < 0.0001), a higher monocyte count (P = 0.002), and showed a trend with current smoking (P = 0.051), whereas dICH subtype was correlated with low serum total cholesterol (P = 0.003), low serum triglycerides (P < 0.0001), and high neutrophil count (P = 0.050). CONCLUSIONS In patients who developed HSVD-related stroke, high monocyte count, current smoking, and hyperlipidemia are prothrombotic factors related to LI, whereas low cholesterol and triglyceride values are related to dICH. Monocyte count might be an inflammatory risk marker for the occlusion of small vessels in hypertensive patients.