Respiratory muscle metabolic activity on PET/CT correlates with obstructive ventilatory defect severity and prognosis in patients undergoing lung cancer surgery

Background and Objective

Respiratory muscle activity is increased in patients with chronic respiratory disease. ¹⁸F-FDG-PET/CT can assess respiratory muscle activity. We hypothesized that respiratory muscles metabolism was correlated to lung function impairment and was associated to prognosis in patients undergoing lung cancer surgery based on the research question whether respiratory muscle metabolism quantitatively correlates with the severity of lung function impairment in patients? Does respiratory muscle hypermetabolism have prognostic value?

Methods

Patients undergoing ¹⁸F-FDG-PET/CT and pulmonary function tests prior to lung cancer surgery were identified. Maximum Standardized Uptake Value (SUVm) were measured in each respiratory muscle group (sternocleidomastoid, scalene, intercostal, diaphragm), normalized against deltoid SUVm. Respiratory muscle hypermetabolism was defined as SUVm >90th centile in any respiratory muscle group. Clinical outcomes were collected from a prospective cohort.

Results

One hundred fifty-six patients were included, mostly male [110 (71%)], 53 (34%) with previous diagnosis of COPD. Respiratory muscle SUVm were: scalene: 1.84 [1.51–2.25], sternocleidomastoid 1.64 [1.34–1.95], intercostal 1.01 [0.84–1.16], diaphragm 1.79 [1.41–2.27]. Tracer uptake was inversely correlated to FEV1 for the scalene (r = −0.29, p < 0.001) and SCM (r = −0.17, p = 0.03) respiratory muscle groups and positively correlated to TLC for the scalene (r = 0.17, p = 0.04). Respiratory muscle hypermetabolism was found in 45 patients (28.8%), who had a lower VO₂ max (15.4 [14.2–17.5] vs. 17.2 mL/kg/min [15.2–21.1], p = 0.07) and poorer overall survival when adjusting to FEV1% (p < 0.01).

Conclusion

Our findings show respiratory muscle hypermetabolism is associated with lung function impairment and has prognostic significance. ¹⁸F-FDG/PET-CT should be considered as a tool for assessing respiratory muscle activity and to identify high-risk patients.     

Place de la chirurgie robotique dans les pathologies tumorales thoraciques

Videothoracoscopy (VTC) has found its place in minimally invasive thoracic surgery, with a wide range of indications: mediastinal conditions (myasthenia gravis, thymoma, neurogenic tumours) and lung diseases (lung cancer, lung metastases). VTC has also enabled the development of robot-assisted thoracic surgery (RAV). VTC and RAV enable closed thoracic surgical procedures to be performed, but with different tools. The post-operative objectives are the same: reduction in morbidity and mortality rates, early rehabilitation, improvement in quality of life and improvements in long-term results. The short- and medium-term results of both of these techniques are also the same. RAV has seen considerable developments in France in terms of its indications, surgical volume and its distribution across numerous academic and private centres. Some exereses would be more simplistic, and likely to be more reproducible from a technical point of view via RAV than with VTC. For example: mediastinal exereses and pulmonary segmentectomies, where RAV appears to be a more appropriate route than VTC. The cost of robotics in thoracic surgery is yet to be determined compared with classic minimally invasive surgery, but any difference is not likely to put a stop to its development. Finally, RAV has teaching implications through simulations and also the integration of modern imaging techniques, which will allow better preparation for the surgical procedure and ensure it is as safe as ultimately possible.     

Endoluminal angioplasty of the superior mesenteric artery in the treatment of intestinal angina]

The authors report about the case of a 69-year-old patient suffering from intestinal angina, in whom an endoluminal angioplasty of the superior mesenteric artery for a stenosis located 3 cm from the ostium allowed suppressing the symptoms. The published series of arterial angioplasty for gastrointestinal care are still rare, but they indicate that angioplasty may be an interesting alternative to or a complement to surgery for patients with intestinal angina.     

Secular trends in breastfeeding and parental smoking

To explore the association between smoking and breastfeeding, we obtained data from a retrospective questionnaire-based national survey comprising a random sample (n = 34 799) of all mothers giving birth in Norway 1970-91. Variables studied were postpartum smoking habits for both parents, duration of breastfeeding, infant's year of birth and parental age. The response rate was 70% (n = 24 438). During the study period, the maternal postpartum smoking prevalence decreased from 38% to 26%. The proportion breastfeeding at 6 months increased from 15% to 44% among smokers, and from 30% to 72% among non-smokers. In spite of a considerable increase in breastfeeding both among smokers and non-smokers, the proportion of breastfeeding, non-smoking women at 6 months was twice that of smoking women during the whole period. Furthermore, the duration of breastfeeding was shorter among young mothers and when the fathers were smoking. There was epidemiological evidence that the effect on breastfeeding of smoking might represent both biological and social mechanisms.     

Temporary quadriplegia following continuous thoracic paravertebral block

A case of temporary quadriplegia following a continuous thoracic paravertebral block in an adult patient scheduled for video-assisted thoracoscopy is presented. An 18-gauge Tuohy needle was inserted under direct vision by the surgeon but the tip of the catheter was not localized. Postoperatively, the patient developed temporary quadriplegia 90 minutes after the start of a continuous infusion of ropivacaine 0.2%. Imaging studies showed that the catheter was localized in the intrathecal space.     

Metabolite ratios as potential biomarkers for type 2 diabetes: a DIRECT study

Aims/hypothesis

Circulating metabolites have been shown to reflect metabolic changes during the development of type 2 diabetes. In this study we examined the association of metabolite levels and pairwise metabolite ratios with insulin responses after glucose, glucagon-like peptide-1 (GLP-1) and arginine stimulation. We then investigated if the identified metabolite ratios were associated with measures of OGTT-derived beta cell function and with prevalent and incident type 2 diabetes.

Methods

We measured the levels of 188 metabolites in plasma samples from 130 healthy members of twin families (from the Netherlands Twin Register) at five time points during a modified 3 h hyperglycaemic clamp with glucose, GLP-1 and arginine stimulation. We validated our results in cohorts with OGTT data (n = 340) and epidemiological case–control studies of prevalent (n = 4925) and incident (n = 4277) diabetes. The data were analysed using regression models with adjustment for potential confounders.

Results

There were dynamic changes in metabolite levels in response to the different secretagogues. Furthermore, several fasting pairwise metabolite ratios were associated with one or multiple clamp-derived measures of insulin secretion (all p < 9.2 × 10^?7). These associations were significantly stronger compared with the individual metabolite components. One of the ratios, valine to phosphatidylcholine acyl-alkyl C32:2 (PC ae C32:2), in addition showed a directionally consistent positive association with OGTT-derived measures of insulin secretion and resistance (p ≤ 5.4 × 10^?3) and prevalent type 2 diabetes (OR_{Val_PC ae C32:2} 2.64 [β 0.97 ± 0.09], p = 1.0 × 10^?27). Furthermore, Val_PC ae C32:2 predicted incident diabetes independent of established risk factors in two epidemiological cohort studies (HR_{Val_PC ae C32:2} 1.57 [β 0.45 ± 0.06]; p = 1.3 × 10^?15), leading to modest improvements in the receiver operating characteristics when added to a model containing a set of established risk factors in both cohorts (increases from 0.780 to 0.801 and from 0.862 to 0.865 respectively, when added to the model containing traditional risk factors + glucose).

Conclusions/interpretation

In this study we have shown that the Val_PC ae C32:2 metabolite ratio is associated with an increased risk of type 2 diabetes and measures of insulin secretion and resistance. The observed effects were stronger than that of the individual metabolites and independent of known risk factors.

     

Prevalence of obstructive lung disease in a general population: relation to occupational title and exposure to some airborne agents.

BACKGROUND: The importance of occupational exposure to airborne agents in the development of obstructive disease is uncertain. Studying the relation in a community population has the benefit of reducing the healthy worker effect seen in studies of working populations. METHODS: The prevalence of obstructive lung disease was examined in a Norwegian general population aged 18-73 in a two phased cross sectional survey. In the second phase a stratified sample (n = 1512) of those responding in the first phase was invited for clinical and spirometric examination (attendance rate 84%). Attenders were asked to state all jobs lasting greater than 6 months since leaving school and to say whether they had been exposed to any of seven specific agents and work processes potentially harmful to the lungs. RESULTS: The prevalence of asthma and chronic obstructive lung disease was 2.4% and 5.4%, respectively; spirometric airflow limitation (FEV1/FVC less than 0.7 and FEV1 less than 80% of predicted values) was observed in 4.5% of the population. All jobs were categorised into three groups according to the degree of potential airborne exposure. Having a job with a high degree of airborne exposure increased the sex, age, and smoking adjusted odds ratio for obstructive lung disease (asthma and chronic obstructive lung disease) by 3.6 (95% confidence interval 1.3 to 9.9) compared with having a job without airborne exposure; the association with spirometric airflow limitation was 1.4 (0.3 to 5.2). Occupational exposures to quartz, metal gases, aluminium production and processing, and welding were significantly associated with obstructive lung disease after adjusting for sex, age, and smoking habit, the adjusted odds ratios varying between 2.3 and 2.7. Occupational exposure to quartz and asbestos was significantly related to spirometric airflow limitation in people older than 50. CONCLUSION: Occupational title and exposure to specific agents and work processes may be independent markers of obstructive lung disease in the general population.     

No difference in self reported health among coalminers in two different shift schedules at Spitsbergen, Norway, a two years follow-up

This study was performed among coal miners in the remote location Svea, Spitsbergen. The shift schedule used to be 7 d on and 7 d off. The aim of this study was to investigate possible changes in health after a voluntary implementation of a new shift schedule, with periods of 14 d on and 14 d off, for 74 percent of the workers in 2007. A questionnaire was distributed to all employees before and two times after the new shift schedule, comprising questions on type of work, shift schedule, pain, sleep, stress and coping. Ninety nine percent of the employees responded; 274 in 2006, 307 in 2007 and 312 in 2008. Work neither in the 14/14 shift nor 7/7 shift was related to any change in the health after these two years. The coping index for workers in the 14/14 shift improved.