Plasma YKL-40 in Inuit and Danes

Alcohol drinking modified the effect of plasma YKL-40 levels on stroke-specific mortality of acute ischemic stroke

OBJECTIVES

Our study aimed to evaluate the association between plasma human cartilage glycoprotein-39 (YKL-40) and stroke-specific mortality at two years in acute ischemic stroke patients according to the drinking status and amount of alcohol consumption. We further investigated the effect of the interaction between these conditions and YKL-40 levels on the outcome.

METHODS

We measured plasma YKL-40 levels in 3267 participants from the China Antihypertensive Trial in Acute Ischemic Stroke. Outcome data on stroke-specific mortality were collected at two years after stroke onset.

RESULTS

During the two years of follow-up, 208 (6.4 %) patients, including 44 drinkers and 164 nondrinkers, died of stroke-specific causes. The patients in the highest quartile of YKL-40 had a 3.52-fold (95 % CI: 1.15-10.76, P for trend = 0.006) risk of stroke-specific mortality compared with those in the lowest quartile among drinkers. However, no significant association between YKL-40 and the outcome was observed among nondrinkers (HR: 1.18, 95 % CI: 0.75-1.86, P for trend = 0.08). Alcohol drinking modified the effect of YKL-40 on the outcome (P for interaction = 0.04). Subgroup analyses revealed that each 1-unit increase in log-transformed YKL-40 was associated with a 72 % greater risk of stroke-specific mortality for light drinkers. This association was amplified with a 226 % increased risk of the outcome among heavy drinkers.

CONCLUSIONS

Elevated YKL-40 levels were associated with an increased risk of stroke-specific mortality at two years among drinkers with ischemic stroke. Drinking status substantially modified the effect of plasma YKL-40 levels on the outcome. This effect was amplified with the increased amount of alcohol consumption.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01840072.

Vitamin D-rich marine Inuit diet and markers of inflammation - a population-based survey in Greenland

The traditional Inuit diet in Greenland consists mainly of fish and marine mammals, rich in vitamin D. Vitamin D has anti-inflammatory capacity but markers of inflammation have been found to be high in Inuit living on a marine diet. Yet, the effect of vitamin D on inflammation in Inuit remains unsettled. This led us to investigate the association between vitamin D and markers of inflammation in a population with a high intake of a marine diet. We studied 535 Inuit and non-Inuit living in West and East Greenland. Information concerning dietary habits was obtained by interview-based FFQ. Blood samples were drawn for analysis of 25-hydroxyvitamin D, high-sensitivity C-reactive protein (hsCRP) and chitinase-3-like protein 1(YKL-40). Participants were divided into three groups based on degree of intake of the traditional Inuit diet. The diet groups (Inuit diet/mixed diet/imported foods) were associated with vitamin D levels in serum (74·2, 69·8 and 52·9 nm; P < 0·001), hsCRP (1·6, 1·4 and 1·3 mg/l; P = 0·002) and YKL-40 (130, 95 and 61 ng/ml; P < 0·001), respectively. YKL-40 level decreased with rising vitamin D level in Inuit (Inuit diet P = 0·002; mixed diet P = 0·011). YKL-40 was lower in groups with higher vitamin D levels after adjusting for other factors known to influence inflammation (P < 0·001). This was not seen for hsCRP. In conclusion, vitamin D and markers of inflammation vary in parallel with the intake of the marine Inuit diet. Vitamin D levels were inversely associated with YKL-40 levels, but no association with hsCRP was found. The hypothesised anti-inflammatory effect of vitamin D was not supported. Other factors in the marine diet may be speculated to influence inflammation.