Objective: It is now well recognized that obesity is a major public health concern, and its prevalence has tremendously increased worldwide over the last decades, including Tunisia. As obesity is associated with cardiovascular diseases, the purpose of this study was to investigate the effect of obesity on forearm skin blood flow (FSBF) response to acetylcholine (Ach), an endotheliumdependent vasodilator, in Tunisian women over a wide range of body mass indices (BMIs). Subjects: One hundred and eighty healthy women with an average age of 34 ± 6 years, an average height of 162 ± 7 cm and an average weight of 78±19 kg participated in this investigation. The mean BMIs of the 60 lean, 50 overweight and 70 obese subjects were 22.1 ± 0.3, 27.7 ± 0.2 and 38.4 ± 0.7 kg m À2 , respectively. Measurements: The FSBF was measured non-invasively using a laser Doppler flowmeter in response to local infusion of a cumulative dose of Ach. Results: After adjusting for age, the mean response of FSBF to Ach was significantly greater in lean (1168%±78) than in overweight (643% ± 38) and obese subjects (323% ± 18) (P ¼ 0.002; Po0.0001, respectively), suggesting a reduction of the endothelium-dependent nitric oxide (NO) release by obesity. Our regression analysis also revealed that the maximum FSBF response to Ach (that is, its efficacy) was inversely correlated with BMI, waist and hip circumferences (r ¼ À0.994, P ¼ 0.002; r ¼ À0.2, Po0.0001, and r ¼ À0.321, P ¼ 0.001, respectively). Conclusion: Our data demonstrate a reduction of skin vasodilatory reserve in obese patients and suggest a defect of both endothelial-dependent relaxation and wall compliance associated with obesity.

The purpose of this study was to investigate whether 6‐min walk test (6MWT) would improve the forearm skin blood flow (FSBF) response to acetylcholine (ACh), an endothelium‐dependent vasodilator, in Tunisian women over a wide range of BMI. The FSBF was measured noninvasively using a laser Doppler flowmeter in response to local infusion of a cumulative dose of ACh, before and after the 6MWT for 102 healthy women; the results were expressed as percentage of baseline. The 6MWT was monitored and recorded. The mean response of FSBF to ACh was significantly greater before as well as after the 6MWT in lean (1,235 ± 123% vs. 1,644 ± 140%) than in overweight (630 ± 62% vs. 1,080 ± 66%) and obese subjects (402 ± 38% vs. 795 ± 40%) (P < 0.0001). Our regression analysis also revealed that the maximal FSBF response to ACh (i.e., its efficacy) was inversely correlated with BMI both before as well as after the 6MWT (r = −0.828, P < 0.0001; r = −0.859, P < 0.0001, respectively), and the efficacies of ACh in the three groups were all significantly elevated following the 6MWT (P < 0.0001). As indicated by ANOVA test, the 6MWT improved the FSBF responses of the lean, overweight, and obese subjects, by 33, 71, and 98%, respectively. We confirm that obesity induced a reduction of skin vasodilatory reserve and altered both endothelial‐dependent relaxation and wall compliance. However, our new data clearly demonstrated that the 6MWT not only improved significantly the FSBF responses in the three groups of women, but the obese patients appeared to benefit more from the 6MWT than the overweight and the lean subjects.

Objective: The specific objective of this investigation was to determine whether bronchopulmonary responsiveness (BPR) to methacholine (MCH) was associated with the body mass index (BMI) of Tunisian women. Subjects: In all, 160 healthy nonsmoker women (52 lean, 45 overweight and 63 obese) were recruited and examined in the Clinical Laboratory of Physiology located in the Medical School of Sousse. The average ages ( ± s.e.) of the three categories of lean, overweight and obese subjects were 27.7±1.1, 33.2±1.7 and 37.5±1.3 years, respectively. Their corresponding mean BMIs ( ± s.e.) were 21.9 ± 0.3, 27.7 ± 0.2 and 36.5 ± 0.8 kg m À2 , respectively. Measurements: Before their inclusion into the study, subjects were screened for their lung status by measuring their pulmonary function testing parameters using a whole body plethysmograph. BPR was assessed, using a cumulative concentration response curve technique, by measuring with a spirometer the decrease in forced expiratory volume in 1 s (FEV 1 ) in response to a cumulative dose of MCH. Results: After adjusting for age, significant differences in both FEV 1 and forced vital capacity (VC) were found between the obese and lean groups (Po0.01), as well as between the obese and overweight groups (Po0.01). In addition, forced expiratory flow between 25 and 75% of VC was significantly different between the obese and lean groups (Po0.001), as well as between the lean and overweight groups (P ¼ 0.015). The mean maximum fall of FEV 1 in response to MCH challenge was significantly higher for the obese group (12.0%) than for the overweight (9.8%) or the lean (6.6%) group (Po0.01). Furthermore, the efficacy of the MCH agonist promoting the maximal response (E max ) and its potency or effective dose producing 50% of the maximal response (ED 50 ) were both associated with BMI (the higher the BMI, the higher the E max and the lower the ED 50 ). Conclusion: Our data clearly show that obesity affects pulmonary function performance in Tunisian women by potentially promoting their bronchial hyperreactivity as suggested by the significant correlation between their BMI and the efficacy of the MCH, as well as its potency.