Does Dietary Polyunsaturated Fatty Acid Intake Associate With Bone Mineral Density and Limb Structural Changes in Early Rheumatoid Arthritis?

Background

Rheumatoid arthritis (RA) is an inflammatory disease that can result in bone erosion, lean mass lowering, and increase of fat mass without changes in body weight. The dietary consumption of polyunsaturated fatty acids (PUFAs) has been assessed in many studies due to their potential anti-inflammatory effect.

Aim

The aim of this research was to identify if dietary intake of PUFAs associates with bone mineral density (BMD) and limb structural changes in early rheumatoid arthritis (ERA) compared to a population-based control group. The study was conducted because previous results have been insufficient.

Methods

The study group consisted of 83 ERA patients and 321 control subjects. A dual-energy X-Ray absorptiometry (DXA) machine was used to measure hip, lumbar spine, and radius BMD, as well as arm and leg fat, lean, and bone mass. Dietary habits and inflammatory markers were assessed to evaluate the effects to BMD and limb structural changes.

Results

In ERA subjects, higher dietary consumption of PUFAs was associated with a decrease in arm fat mass (b -28.17, P = .02) and possibly with higher lumbar BMD (b 0.008, P = .058). Limb bone and lean mass changes were not associated with dietary intake of PUFAs.

Conclusion

Balanced nutrition is essential. Consuming PUFAs could be beneficial in ERA preventing structural changes to hands, but additional research is needed.

Factors associated with hand bone changes in early rheumatoid arthritis

BACKGROUND

The aim of this research was to assess if hand bone mineral density (HBMD) changes associated with the appearance of erosions in early rheumatoid arthritis (ERA), compared with the population-based control group. Additionally, we tried to identify if there are novel factors that associate with HBMD and erosive changes (EC), and if they are dissimilar. The study was conducted as the data are limited.

METHODS

The study group consisted of 83 ERA patients and 321 controls. Dual-Energy X-Ray Absorptiometry (DXA) machine was used to measure HBMD. EC of RA (rheumatoid arthritis) were assessed in X-rays of hands using Sharp scores. Life-style habits, inflammation markers were assessed to evaluate the effects of different factors.

RESULTS

The presence of ERA was associated with lower HBMD compared with controls (adjusted for age, gender, height and weight; b -0.01, p = 0.045). 76% (95% CI 65.3-84.6) of ERA patients had EC in hand X-ray. Smoking habits and higher BMI (body mass index) were associated with an increased likelihood of having RA specific EC. In ERA, decreasing of HBMD was associated with the elevation of interleukin-6 (IL-6) and rheumatoid factor (RF) positivity.

CONCLUSIONS

In ERA, HBMD changes were not associated with the appearance of erosions. Factors that associate in ERA with HBMD changes and appearance of erosions differ. HBMD assessment together with serum IL-6 level could be useful in everyday clinical practice for better surveillance of ERA patients who do not have EC in hand X-rays.

Factors Associated With Low Lean Mass in Early Rheumatoid Arthritis: A Cross- Sectional Study

Background and Objectives: The aim of the study was to evaluate body composition (BC) of rheumatoid arthritis (RA) patients at disease onset compared to population controls focusing on the associations between low lean mass and disease specific parameters, nutritional factors and physical activity. Materials and Methods: 91 patients with early rheumatoid arthritis (ERA) (72% female) and 328 control subjects (54% female) were studied. BC- lean and fat mass parameters were measured with a Lunar Prodigy Dual Energy X-Ray Absorptiometry (DXA) machine. The prevalence, age and gender adjusted odds ratios of having low lean mass and overfat, associations between nutrition, physical activity, and ERA disease specific parameters and the presence of low lean mass were evaluated. Results: We found that the BC of patients with recent onset RA differs from control subjects-ERA patients had a higher mean body fat percentage (BFP) and lower appendicular lean mass (ALM). 41.8% of the ERA patients and 19.8% of the controls were classified as having low lean mass adjusted OR 3.3 (95% C.I. 1.9-5.5, p < 0.001). 68.1% of the ERA subjects and 47.3% of the controls were overfat (adjusted OR 1.9 (95% C.I. 1.1-3.3, p = 0.02)) and the adjusted odds of having both low lean mass and overfat were 4.4 times higher (26.4% vs. 7.0% 95% C.I. 2.3-8.4, p < 0.001) among the ERA group. Higher ESR (OR 1.03, C.I.1.002-1.051, p = 0.03), CRP (OR 1.03, C.I. 1.002-1.061, p = 0.04), lower protein intake (OR 0.98 C.I. 0.96-0.99, p = 0.04), corticosteroid usage (OR 3.71 C.I. 1.4-9.9, p < 0.01) and lower quality of life (higher HAQ score OR 2.41 C.I. 1.24-4.65, p < 0.01) were associated with having low lean mass in the ERA group (adjusted to age and gender). Conclusions: Patients with early RA have lower appendicular lean mass and higher body fat percentage compared to healthy controls. Loss of lean mass in early RA is associated with elevated inflammatory markers inducing catabolism, lower protein intake and also with GCS treatment.

Insulin Resistance in Early Rheumatoid Arthritis Is Associated with Low Appendicular Lean Mass

In established rheumatoid arthritis (RA), the presence of insulin resistance (IR) is well proven but, in the early stage of the disease, data are inconclusive. We evaluated the presence of IR and associations with body composition (BC) parameters among early RA (ERA) and control subjects. The study group consisted of 92 ERA and 321 control subjects. Using homeostatic model assessment of IR (HOMA-IR), the cut-off value for IR was 2.15. 56% of the ERA patients and 25% of the controls had IR. Of the BC parameters, patients with early RA had less fat-free mass and appendicular lean mass (ALM). In multivariable model, ERA group (b-Coefficient) (4.8, CI: 2.6-8.8), male gender (7.7, CI: 2.7-22.1), and fat mass index (1.2, CI: 1.1-1.4) were associated with IR. Insulin-resistant ERA patients had higher inflammatory markers and higher disease activity. In the multivariable model in the ERA group, IR was associated with male gender (b-Coefficient) (7.4, CI: 153-34.9), high disease activity (6.2, CI: 1.7-22.2), and lower ALM (0.03, CI: 0.001-0.97). IR develops in the early stage of RA in the majority of patients. IR is more common among males and is associated with RA disease activity and lower ALM.