The nutritional impact of rheumatologic diseases was first identified in 1873 by Sir James Paget and given the name rheumatoid cachexia.1,2 It is associated with inflammatory diseases1 and comprises the effects of nutritional alterations on motor and sensory functions, manifested by a combination of weakness, muscle atrophy and loss of functionality.1,3

Although some authors suggest that the altered nutritional state of patients with rheumatologic diseases is a marker for disease severity,3 there are still aspects that deserve more attention.

In recent decades, the concept of rheumatoid cachexia has received more consideration2 based on the understanding of how nutritional alterations affect patient quality of life, evolution and the prognosis of rheumatologic conditions.3 Advances have also been made in our comprehension of the pathophysiological mechanisms that mediate the nutritional impact of inflammatory diseases (acute and/chronic).4,5 Meanwhile, the tools available for evaluating body composition have become more precise and can more adequately define the effects of inflammatory conditions on lean mass, fat mass and energy expenditure.6

From a pathophysiological standpoint, the importance of preventing the loss of lean mass stems from the fact that it is largely created by what is known as body cell mass and is the site where 95% of the metabolic activity of the body occurs.2,6–8

Lean mass is composed of muscle, functional organ tissue, the immune system and the skeletal system, with their related structural, metabolic, immunological, support and motor functions.2,6–8 Therefore, any alteration in lean mass would mean the loss or limitation of body functions and potential morbidities or mortality.6,8,9

It is well known that rheumatology patients with altered nutritional states have life expectancies that are up to 18 years shorter than patients with rheumatologic diseases without malnutrition; in addition, their risk for morbidity is 3–5 times higher than the general population.3 Mortality associated with malnutrition (infectious processes, cardiovascular and pulmonary diseases) even surpasses that of the morbidities associated with rheumatologic diseases.3,6

The concept of malnutrition in patients with chronic inflammatory conditions covers the clinical spectrum from underweight patients with reduced muscle mass to those patients who, according to their body mass index (BMI), are overweight or obese but also have decreased muscle mass associated with chronic inflammatory processes.4,5,8 At the same time, increased fat mass is a risk factor for the development of metabolic syndrome and cardiovascular diseases, whose prevalence is widespread in patients with rheumatologic diseases.2–10

The incidence of rheumatoid cachexia is variable and depends directly on the sensitivity and specificity of the instruments used for its detection.11,12 The prevalence of nutritional alterations ranges from 4% to 26%–52%, particularly in populations with rheumatoid arthritis.11,13

A published study by Bravo-Ramírez et al.14 reported that 37.5% of the Mexican population with Systemic lupus erythematosus (SLE) had decreased lean body mass when they were evaluated with bioelectrical impedance vector analysis despite the fact that half of the sample had obese or overweight body mass indices.

In another study, also in Mexican patients with diagnosed rheumatoid arthritis (RA),13 48% of patients had decreased lean body mass, even when 94% had increased fat mass percentages. It is therefore evident that the prevalence of malnutrition, according to the criterion of decreased lean mass, is frequently underestimated.

The prevalence of malnutrition also varies depending on the gender of the population studied: in patients with RA, it can reach 52% in women and 30% in men.11

In patients with malnutrition, the decrease in underlying lean mass is not always evident because, if there is preserved or increased fat mass, body weight is not modified.2,3,11,12 BMI can be within normal, overweight or even obese ranges, so patients are erroneously considered well nourished.2,11–14

In a population of Mexican women diagnosed with SLE evaluated by means of BMI, 20.5% and 29.2% were found within overweight and obese ranges, respectively. However, when an evaluation tool with greater sensitivity was used to estimate lean mass, such as bioelectrical impedance vector analysis, 37% of this population had decreased lean body mass and met criteria for malnutrition (cachexia). This condition would have gone undetected if only BMI had been evaluated.14

Thus, patients with chronic inflammatory diseases should be evaluated from a nutritional standpoint both systematically and periodically using a combination of instruments and tools with high sensitivity for the detection of alterations in body composition, even when patients show no or very slight changes in body weight.2,3,11,12 The resources available for assessing nutritional state in patients with rheumatologic diseases include nutritional screening scales, anthropometric measurements, dietary history, interpretation of biochemical parameters, functional evaluation and determination of body composition, the latter using bioelectric impedance, densitometry, computed tomography, magnetic resonance, muscle ultrasound, etc.6

In order to extend the diagnostic capacity of malnutrition in rheumatology patients, it is currently recommended to use resources with greater sensitivity than anthropometrics and BMI to detect nutritional alterations, particularly in lean mass and function,1–8 even when the BMI is within normal, overweight or obese ranges.4,6

Currently, malnutrition is classified into 3 clinical entities according to the pathophysiologic mechanisms involved in their development. This provides better understanding and integration of clinical-pathophysiologic aspects and the possibility to influence prevention, identification and management.4,5,8

The conceptual focus on the pathophysiologic processes that lead to malnutrition, and not just the degree of correspondence with cut-points established for anthropometric measurements or amounts of lean mass and fat mass, is currently considered an innovative proposal for the comprehension, prevention and the management of malnutrition.4,5,18,29–31 With these grounds, it is possible to implement specific strategies for the management of malnutrition, whose main objectives are:

• –

  Nutritional management as an integral and interdisciplinary part of the medical management of patients with rheumatologic diseases.6,13

• –

  Methods to evaluate body composition and provide a better definition of the effect that rheumatologic diseases have on lean mass and fat mass, thus increasing understanding, knowledge, prevention and management of nutritional alterations in order to reduce the impact on the course and prognosis of the disease, quality of life and funcionality.6

• –

  Preservation of body composition, particularly with the conservation of lean mass and related functionality.2,9,10,13,26

• –

  Prevention of increased body mass, excess weight gain, obesity and metabolic syndrome and their participation as risk factors for the development of cardiovascular diseases.13,20–25

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  Reduction of the incidence and prevalence of nutritional alterations associated with the pathophysiological basis of rheumatologic diseases by optimally controlling the baseline disease; prevention, identification and management of acute concomitant processes, as well as minimisation of potential side effects of treatment on nutritional state.2,18

• –

  Preservation of functionality, independence, autonomy, self-sufficiency and quality of life, with improved prognosis and life expectancy.6,9,10,26

• –

  Potential use of pharmaconutrition to selectively modulate the underlying inflammatory response and influence the prognosis of the rheumatologic disease, even when this method of management is still under debate.28,32

To this end, proposed nutritional interventions include:

• –

  Nutritional screening and evaluation of patients with rheumatologic diseases for the presentation, identification, diagnosis and management of the nutritional alterations associated with rheumatologic diseases.33

• –

  Dietary prescription, monitoring and follow-up to maintain adequate macro and micronutrients that cover basic nutritional requirements as well as any requirements of the chronic disease, acute concomitant processes and those associated with the potential side effects of the drugs used for the management of rheumatologic diseases.13,33

• –

  Rehabilitation programmes to preserve bone density, muscle mass and strength in order to maintain functionality, independence, autonomy, prevent disability and improve the quality of life of patients with rheumatologic diseases.34–38

• –

  Selective modulation of inflammatory processes to attenuate the metabolic response that accompanies rheumatologic diseases and its effects on nutritional state and body composition.39–43

The patient is a 47-year-old woman with type 2 diabetes, hypertension, hypercholesterolaemia and hypertriglyceridaemia. She had been diagnosed with RA 6 years ago and currently showed evidence of articular inflammatory activity with phlogosis of the elbows and knees. The patient was admitted to the hospital with a diagnosis of community-acquired pneumonia.

Irregular pharmacological management for baseline diseases had included metformin, enalapril, prednisone, methotrexate and chloroquine. Her usual weight was 78.5kg and current weight was 65.5kg; weight loss of 13kg had occurred over the last 12 months. BMI was 26.2kg/m2 (overweight). Ankle oedema was observed in both legs.

The evaluation of her daily eating habits identified high consumption of complex carbohydrates and low intake of protein.

Anthropometric assessment showed: mid-arm circumference 26.8cm (below 10th percentile44); abdominal circumference 97cm (higher than the reference point for the Spanish population45).

Body composition was analysed by vector impedance, which revealed lean mass (10th percentile46) and high fat mass (95th percentile46).

Given this assessment of lean mass using bioelectrical impedance vector analysis of the body composition, the patient was cachectic47 (Fig. 1), with the additional presence of sarcopenic obesity (increased fat mass and reduced fat mass).6,48

Fig. 1.

Body composition analysed by bioelectrical impedance vector analysis.

(0.09MB).

Functional evaluation with dynamometry showed a muscle strength of 14kg (10th percentile49).

Nutritional considerations:

• 1.

  Patient with morbidities associated with malnutrition, chronic inflammatory state, use of glucocorticoids, metabolic syndrome and acute infectious inflammatory process.

• 2.

  Despite having a BMI in the overweight range, the patient was malnourished as she has lost 16.5% of her usual weight over the course of the last 12 months.

• 3.

  There was a loss of lean muscle (mid-arm circumference in 10th percentile44 and fat-free mass in 10th percentile46).

• 4.

  Given the body composition defined by bioelectrical impedance vector analysis, the patient was cachectic (decreased lean mass and overhydration).47

• 5.

  Functional effects of decreased lean mass with loss of grip strength (dynapenia).49

• 6.

  Along with the loss of lean mass, fat mass was increased (body mass index in 95th percentile46), which added the entity of sarcopenic obesity.6,48

• 7.

  Fat mass was concentrated in the abdominal area, and abdominal circumference was higher than normal for women in this population group.45

• 8.

  The aetiology of the malnutrition was multifactorial2,8,9:

  • –

    Malnutrition associated with chronic inflammatory process (rheumatologic cachexia): RA and metabolic syndrome, and possible additional effects of the drugs used (glucocorticoids).

  • –

    Malnutrition associated with acute inflammatory processes, exacerbation of baseline disease, with inflammatory activity of the joints and inflammatory/infectious pulmonary process.

  • –

    Malnutrition associated with low protein intake and increased caloric intake from carbohydrates.

• 9.

  Patient with morbidity associated with malnutrition as well as increased cardiovascular risk due to a high level of body fat, particularly in the abdominal area, and metabolic syndrome.45

• 10.

  Proposed medical/nutritional management strategy:

  • –

    Resolution of the acute infectious inflammatory process.

  • –

    Optimal pharmacological management of the baseline rheumatologic disease, metabolic control (diabetes mellitus and dyslipidaemia) and hypertensive treatment.

  • –

    Prescribed diet for adequate nutrition.

In summary, nutritional alterations are prevalent in patients with rheumatologic diseases. Their diagnosis depends on the nutritional assessment tools used. We suggest the preferable use of instruments that provide the objective evaluation of body composition, particularly those that estimate or measure lean body mass.

The aetiology of nutritional alterations in rheumatologic diseases is multifactorial. A combination of variable degrees of malnutrition may be observed in association with chronic inflammatory processes (rheumatoid cachexia), malnutrition associated with inflammatory processes and malnutrition associated with inadequate nutrition.

The presence of malnutrition in patients with rheumatologic diseases has an impact on prognosis, quality of life, autonomy, independence and even mortality.

The coexistence of malnutrition with a reduction in lean mass coinciding with increased fat mass (sarcopenic obesity) is frequent, which at the same time increases the risk for cardiovascular disease.

Interdisciplinary strategies are required for the prevention, identification, diagnosis and management of the nutritional alterations associated with rheumatologic diseases.

A focus on nutrition should form part of the integral management of patients with rheumatologic diseases.

None.

None have been declared.