The Effect of Smoking on Diabetes: Investigation of Cotinine’s Effect on Hemoglobin A1c Levels
Author:
Cindy LiuMentors:
- Sean Liu, Professor of Chemistry, California State Polytechnic University Pomona
- John Chan, Professor, California State Polytechnic University Pomona
It has been proven that nicotine in cigarettes has a negative effect on those with diabetes by raising the level of hemoglobin A1c which is the indicator for glycemic control. Cotinine, being the metabolized form of nicotine, might also have an impact of smoking on diabetes because it stays in the body much longer than nicotine. However, the effects of cotinine on diabetes have not been reported. This experiment observed the effects of cotinine on hemoglobin A1c levels, with the hypothesis being that cotinine does raise hemoglobin A1c levels. To see how cotinine affects diabetes, this experiment is designed to determine how different concentrations of cotinine affect levels of hemoglobin A1c, or glycated hemoglobin, commonly used to test diabetics for blood sugar control. High A1c levels indicate poor blood sugar control, so if increasing concentrations of cotinine lead to increasing concentrations of A1c, cotinine may impact diabetics. The procedure consists of making solutions of glucose and human red blood cells, finally added to varying concentrations of cotinine (0.5, 2.0, 5.0 mM). The red blood cells were lysed first before being added to the glucose and cotinine. After incubation for 1 or 2 days, these samples would then undergo boronate affinity chromatography to separate the A1c from the non-glycated hemoglobin. These 2 components would then be compared, by use of a spectrophotometer, to show the percentages of A1c in relation to the amount of cotinine. The results showed that raising cotinine concentrations indeed raised A1c levels. For example, with a 1-day treatment with 5.0 mM cotinine, A1c level was increased by as much as 9.0%. In conclusion, cotinine can cause increased A1c levels and therefore may increase the risk of diabetic complications for smokers.