Chapter 20: Nutrition-Related Diseases

DISORDERS OF CALORIC INTAKE

Obesity

• Multifactorial disease of excess body fat affecting any age group

  • Endogenous: endocrine illness

    • – Hypothyroid, polycystic ovarian syndrome, adrenal hyperandrogenism, imbalance of ghrelin, and leptin

  • Exogenous: positive energy balance is stored as adipose tissue

    • – Excess calories, sedentary lifestyle, minimal exercise

• Clinical manifestations

  • Systemic

    • – Obesity in central areas, mammary region, buttocks

    • – Obesity in limbs, greater in upper arms and thighs; genu varum due to weight-bearing

  • Cutaneous

    • – Acrochordon: increases with severity of obesity, associated with Type 2 diabetes mellitus

    • – Striae distensae: "stretch marks"

    • – Keratosis pilaris: up to 21% of obese patients

    • – Plantar hyperkeratosis: due to increased foot girth and weight bearing

    • – Adiposis dolorosa (Dercum disease): rare, in postmenopausal obese women

      • Multiple symmetric painful lipomas sparing head/neck; commonly on trunk and lower extremities

  • Metabolic alterations

    • – Acanthosis nigricans: insulin resistance, correlates with subsequent development of Type 2 diabetes mellitus if untreated

    • – Polycystic ovarian syndrome (PCOS): infertility, dysmennorhea, insulin resistance, cystic ovaries on ultrasound

    • – Hyperandrogenism secondary to metabolic dysregulation

• Diagnosis: obesity defined as BMI more than 30, or greater than 95% for age and gender

• Treatment

  • Lifestyle and dietary modification: exercise and low-calorie diet

  • Social support: family, friends, provider–patient contact

  • Medications should be used with caution: phentermine, bHCG injections, orlistat

  • Surgical: gastric bypass, or gastric outlet surgeries; necessitate monitoring for nutritional deficiencies, especially B₁₂

Anorexia Nervosa and Bulimia

• Undernourishment due to abnormal patterns of food consumption and/or purging to achieve thinness; related to underlying psychiatric distburances

• Most common in adolescent females

• Clinical manifestations

  • Cutaneous: xerosis, pruritus, lower limb edema, Russell sign (knuckle calluses due to chronic self-induced vomiting)

  • Hair: thinning and increased fragility

  • Oral: gingivitis, tooth enamel erosion, parotid gland enlargement

• Treatment

  • Cognitive behavioral therapy

  • Selective serotonin reuptake inhibitors

  • Hospitalization with parenteral nutrition in severe circumstances

Protein Energy Malnutrition: Undernutrtion, Marasmus, and Kwashiorkor

• Undernutrition: all encompassing term for nutritional and caloric deficiencies (Fig. 20-1A,B)

  • Related to socioeconomic status and availability of nutrients in local region

  • Favors opportunistic infections: reduced cellular immunity, phagocytic function, adaptive immunity (decreased antibody production)

  • Secondary: from HIV, pneumonia, tuberculosis, and malaria

  • Diagnosis: investigate possible infectious etiologies, anemia, nutritional deficiencies (metals, vitamins, etc.)

    • – Urinalysis (UA) (infection), blood smear (malaria), PPD, fecal occult blood, parasites, or ova

• Marasmus: "adapted" starvation from global nutrition deficiency

  • Occurs in developing countries: decreased intake of all macronutrients; rare in developed countries

  • Primary causes: congenital defects (difficulty feeding, degluttition), failure to thrive (neglect, inability to nurse), alcoholism, eating disorders

  • Secondary: lack of nutrient availability, low socioeconomic status, early and incorrect use of infant formula (not enough calories are given)

  • Clinical manifestations

    • – Constitutional: emaciated, growth deficiency, muscular atrophy

    • – Systemic involvement: hypotension, hypoglycmeia, hypothermia, constipation (in infants), anemia

    • – Cutaneous: loss of turgor, thinning of skin, xerosis, loss of elasticity

  • Diagnosis: typically on history and physical examination

  • Treatment: inpatient setting, ...