After an overnight fast and abstaining from smoking, 28 healthy men (mean age 25.4±0.7 years) underwent a total of 36 measurements (8 subjects were examined twice) of gastric emptying of a 99mTc-solid phase labelled meal. On the basis of exact questioning, a cigarette smoking intensity index (CSI) was calculated by multiplying the number of cigarettes smoked a day times the number of years of smoking (median 54, range 0 to 300). The mean gastric transit time, MTT90, was compared among three classes of CSI: I, the lower quartile (0 < CSI≤11.5), II - the interquartile range (11.5 < CSI≤155), and III - the upper quartile (155 < CSI≤300): I (n=10) MTT90=38.07±0.68 min, II (n=17) MTT90=39.92±0.45 min (p=0.027 vs I), and III (n=9) MTT90=39.74±0.45 min (p=0.061 vs I). Cluster analysis revealed three subgroups of the subjects: A - smoking 3.3±2.2 cigarettes a day for 2.0±1.4 years, MTT90 36.32±0.62 min; B - smoking 9.0±2.1 cigarettes a day for 4.2±0.8 years, MTT90 40.26&plusm;0.25 min, p < 0.001 vs A; C - smoking 23.5±2.8 cigarettes a day for 9.1±1.3 years, MTT90 39.81±0.41 min, p < 0.001 vs A.
Conclusions: Gastric emptying of a radiolabelled solid meal is significantly slower in healthy men smoking at least 9 cigarettes a day for at least 4 years.

Keywords: cigarette smoking, Gastric Emptying