Associations between paraspinal muscles fatty infiltration and lumbar vertebral bone mineral density - An investigation by fast kVp switching dual-energy CT and QCT

Purpose

To investigate the relationship between paraspinal muscles fat content and lumbar bone mineral density (BMD).

Methods

A total of 119 participants were enrolled in our study (60 males, age: 50.88 ± 17.79 years, BMI: 22.80 ± 3.80 kg·m^-2; 59 females, age: 49.41 ± 17.69 years, BMI: 22.22 ± 3.12 kg·m^-2). Fat content of paraspinal muscles (erector spinae (ES), multifidus (MS), and psoas (PS)) were measured at (ES L1/2-L4/5; MS L2/3-L5/S1; PS L2/3-L5/S1) levels using dual-energy computed tomography (DECT). Quantitative computed tomography (QCT) was used to assess BMD of L1 and L2. Linear regression analysis was used to assess the relationship between BMD of the lumbar spine and paraspinal muscles fat content with age, sex, and BMI. The variance inflation factor (VIF) was used to detect the degree of multicollinearity among the variables. P < .05 was considered to indicate a statistically significant difference.

Results

The paraspinal muscles fat content had a fairly significant inverse association with lumbar BMD after controlling for age, sex, and BMI (adjusted R ² = 0.584-0.630, all P < .05).

Conclusion

Paraspinal muscles fat content was negatively associated with BMD.Paraspinal muscles fatty infiltration may be considered as a potential marker to identify BMD loss.

Fat mass to fat-free mass ratio and its associations with clinical characteristics in asthma

BACKGROUND

Fat mass to fat-free mass ratio (FM/FFM) assesses the combined effect of the balance between fat mass and fat-free mass.

AIMS

to evaluate the associations beetween FM/FFM and clinical outcomes in asthma and to compare clinical characteristics between individuals with higher and lower FM/FFM.

METHODS

128 participants with asthma underwent anthropometric, spirometry and bioelectrical impedance assessments. Physical activity in daily life (PADL) was assessed by the Actigraph for 7 days. Daily dose of inhaled medication, steps of pharmacological treatment, Asthma Control Questionnaire, Asthma Quality of Life Questionnaire and Hospital Anxiety and Depression Scale were also assessed. Participants were classified into two groups according to the 50th percentile of reference values for FM/FFM.

RESULTS

Individuals with higher FM/FFM (n=75) used higher daily doses of inhaled corticosteroids, had worse lung function and fewer steps/day when compared to those with lower FM/FFM (n=53) (P≤0.021). Associations were found between absolute values of FM/FFM with lung function (FEV₁ and FVC [liters]): R²=0.207 and 0.364;P<0.0001), and between the categories of lower or higher FM/FFM with steps of medication treatment (Cramer's V=0.218;P=0.016) and level of PADL (Cramer's V=0.236;P=0.009). The highest FM/FFM was a determining factor of physical inactivity (OR: 3.21;95%CI:1.17-8.78) and highest steps of pharmacological treatment (OR: 8.89;95%CI:1.23-64.08).

CONCLUSION

Higher FM/FFM is significantly associated with worse clinical characteristics in individuals with asthma, such as higher doses of inhaled corticosteroids, worse lung function and fewer steps/day. Moreover, higher FM/FFM is a determining factor of physical inactivity and the highest steps of pharmacological treatment for asthma.

A ketogenic diet exerts beneficial effects on body composition of cancer patients during radiotherapy: An interim analysis of the KETOCOMP study

Background and aim

Ketogenic diets (KDs) have gained interest as a complementary treatment for cancer patients. Here we present first results of our ongoing KETOCOMP study (NCT02516501) concerning body composition changes among rectal, breast and head & neck cancer (HNC) patients who consumed a KD during curative radiotherapy (RT).

Experimental procedure

Sixty-one patients eating a non-ketogenic diet were compared to 20 patients on a KD supplemented with 10 g essential amino acids on RT days. Body composition was measured prior to and weekly during RT using 8-electrode bioimpedance analysis. Longitudinal body composition data were analyzed using linear mixed effects models.

Results and conclusion

Patients on the KD exhibited nutritional ketosis, defined as serum β-hydroxybutyrate levels ≥0.5 mmol/l, in a median of 69.0% of blood measurements (range 0–100%) performed in our clinic. In rectal and breast cancer patients, KD was significantly associated with a loss of 0.5 and 0.4 kg fat mass per week (p = 0.00089 and 8.49 × 10⁻⁵, respectively), with no significant changes in fat free and skeletal muscle mass. In HNC patients, concurrent chemotherapy was the strongest predictor of body weight, fat free and skeletal muscle mass loss during RT, while consuming a KD was significantly associated with a gain in these measures. These preliminary results confirm prior reports indicating that KDs are safe to consume during standard-of-care therapy. They also provide an important first indication that KDs with ample amino acid intake could improve body composition during RT in curative cancer patients.

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Consumption of a ketogenic diet (KD) during radio(chemo-)therapy is feasible.

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In rectal and breast cancer patients, the KD significantly reduced fat mass.

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Fat-free mass and skeletal muscle mass were preserved by the KD.

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In head and neck cancer patients a KD influenced body composition opposite to chemotherapy.