People who drink and smoke:
Moderate alcohol consumption
Alcohol contains ethanol, which has a series of effects on lipid metabolism. Research has found that heavy drinkers have significantly increased serum total cholesterol, triglycerides, and low-density lipoprotein, especially the latter two, and these patients are at greatly increased risk of hypertension, stroke, and liver cirrhosis.
Smoking is harmful to health and should be avoided
The impact of smoking on serum total cholesterol (TC) levels
The serum TC levels of smokers are usually 10% to 15% higher than those of non-smokers. It was also found that the concentration of carbon monoxide hemoglobin (COHb) in whole blood reaches up to 10% to 20%. It is inferred that the high level of serum TC may be related to the increase in carbon monoxide concentration in blood.
The effect of smoking on serum high-density lipoprotein cholesterol (HDL-C)
Smoking is negatively correlated with serum HDL-C levels. Regardless of gender, smokers have lower serum HDL-C levels than non-smokers by 0.13-0.23 mmol/L (5-9 mg/dL). Smokers also have higher serum triglycerides (TG) and TC/HDL-C levels compared to non-smokers. However, there is a negative correlation between serum HDL-C and TG levels in smokers. The actual mechanism for the low serum HDL-C levels in smokers cannot be explained by changes in TG, and it is currently unknown. It is suspected that the mechanism may be related to carbon monoxide inhibiting hepatic cell mitochondrial synthesis of HDL.
The effect of smoking on serum triglycerides (TG)
Nicotine and carbon monoxide in cigarettes stimulate the release of catecholamines from the sympathetic nerves, increasing plasma free fatty acids. These free fatty acids are eventually taken up by fatty tissue to form TG. Catecholamines also promote the release of lipids from fatty tissue, leading to increased TG levels.
The effect of smoking on serum low-density lipoprotein-cholesterol (LDL-C): Exposure to smoke makes LDL susceptible to oxidation into OX-LDL, suggesting that carbon monoxide may increase the sensitivity of LDL to oxidation.
