Zinc Deficiency in Older Adults Undergoing Rehabilitation With Calcium Pyrophosphate Deposition Disease: A Case Series.

Pseudogout, or calcium pyrophosphate deposition disease (CPPD), is a common form of inflammatory arthritis in older adults. Although metabolic/endocrine factors such as magnesium deficiency and hyperparathyroidism are established risk factors, the role of zinc remains unclear. Since zinc deficiency is prevalent among older adults and zinc influences inflammation control and cartilage metabolism, its potential contribution to CPPD warrants investigation. This study aimed to explore the potential association between zinc deficiency and CPPD in older adults undergoing rehabilitation. We report a case series of five women aged 82-92 years undergoing rehabilitation who developed CPPD. Affected joints included the knees, ankles, wrists, and metatarsophalangeal joints. All patients had serum zinc levels below the reference range (49-67 µg/dL), while other minerals were generally within normal limits. In our study, zinc deficiency was independent of the general malnutrition status. Recurrent CPPD occurred in two patients, particularly those with lower functional status during rehabilitation. This exploratory, hypothesis-generating case series could suggest a potential link between hypozincemia and CPPD in older adults. Lower functional status may also be related to CPPD attacks. While limited by sample size, these findings highlight a clinically relevant hypothesis that warrants further investigation in larger prospective studies.