The Relationship between Serum Insulin-Like Growth Factor I Levels and Ischemic Stroke Risk

Abstract

ObjectiveThe aim of the study was to assess the relationship between insulin-like growth factor I (IGF-I) serum levels and acute ischemic stroke (AIS) in a Chinese population.MethodsAll consecutive patients with first-ever AIS from August 1, 2011 to July 31, 2013 were recruited to participate in the study. The control group comprised 200 subjects matched for age, gender, and conventional vascular risk factors. IGF-I serum levels were determined by chemiluminescence immunoassay. The National Institutes of Health Stroke Scale (NIHSS) score was assessed on admission blinded to serum IGF-I levels.ResultsThe median serum IGF-1 levels were significantly (P = 0.011) lower in AIS patients (129; IQR, 109–153 ng/mL) compared with control cases (140; IQR, 125–159 ng/mL). We found that an increased risk of AIS was associated with IGF-I levels ≤135 ng/mL (unadjusted OR: 4.17; 95% CI: 2.52–6.89; P = 0.000). This relationship was confirmed in the dose-response model. In multivariate analysis, there was still an increased risk of AIS associated with IGF-I levels ≤135 ng/mL (OR: 2.16; 95% CI:1.33–3.52; P = 0.002) after adjusting for possible confounders.ConclusionLower IGF-I levels are significantly related to risk of stroke, independent from other traditional and emerging risk factors, suggesting that they may play a role in the pathogenesis of AIS. Thus, strokes were more likely to occur in patients with low serum IGF-I levels in the Chinese population; further, post-ischemic IGF-I therapy may be beneficial for stroke.

Insulin-Like Growth Factor-1 as a Prognostic Marker in Patients with Acute Ischemic Stroke

“…Several epidemiologic studies have reported an inverse relation between plasma IGF-1 levels and risk of ischemic stroke [11]–[12]. Similarly, Dong et al [13] found that lower IGF-1 levels were significantly related to risk of stroke, independent from other traditional and emerging risk factors in one cohort Chinese patients. Interesting, Selvamani et al [14] found that low-normal levels of IGF-I was associated with increased mortality in ischemic heart disease and stroke.…”

Sex differences in stroke therapies

“…Extensive numbers of clinical studies have shown that lower IGF-1 levels significantly increase the risk of stroke and higher IGF-1 levels are associated with improved stroke outcomes, suggesting the circulating IGF-1 level may be used as a predictive value for ischemic stroke outcome (De Smedt et al 2011; Dong et al 2014; Tang et al 2014) and post-stroke IGF-1 treatment may be beneficial to both sexes. However, a recent study using miRNA that regulate IGF-1 found sex differences in the efficacy of this treatment.…”

Intranasal Insulin and Insulin-Like Growth Factor 1 as Neuroprotectants in Acute Ischemic Stroke

“…It is produced mainly by the liver in response to the endocrine growth hormone stimulus; its bioavailability is regulated by IGF-binding proteins [107, 108], and its actions are mediated by specific membrane receptors, abundantly expressed in the brain [108]. During the normal aging process, IGF-1 levels decline and low IGF-1 levels have been correlated with frailty and decrease in cognitive abilities [111].…”

“…Epidemiologic studies in humans have reported an inverse relation between plasma IGF-1 levels and risk of ischemic stroke [128] Serum IGF-1 levels decline with age, lack of exercise, and in metabolic syndrome, and a low IGF-1 level is independently associated with increased risk of stroke [107]. Low circulating IGF-1 levels are associated with worse outcome after stroke [129, 130] although this correlation should be interpreted cautiously and not taken to necessarily imply a causative link.…”