Smokers who abstain from cigarettes were found to have lowered Hypoxic Ventilatory Response (HVR) according to research published in BMC Pulmonary Medicine.

Past research has found that neonates born to smoking mothers have an attenuated HVR, Dr. Hildebrandt and his team note in BMC Pulmonary Medicine, online November 24. Studies in adult smokers have not found an effect, however, although some have shown an increase in HVR in both smokers and non-smokers exposed to cigarettes, the authors add.

In the new study, they sought to determine whether HVR would be different for smokers and non-smokers once smokers no longer had nicotine in their system. They compared isocapnic HVR in 23 healthy smokers after 12 hours of abstinence and 23 healthy-non smokers.

Factors that affect isocapnic HVR, such as plasma levels of glucose and thiols, were similar in the two groups. However, the HVR, normalized for body mass index, was 0.024 L/min for abstinent smokers, compared to 0.037 L/min for the nonsmokers (p=0.002).

Once they began smoking again, the smokers’ HVR returned to a level similar to that of the nonsmokers.