A Personal Health Record (PHR) is a health information repository controlled and managed directly by a patient or his/her custodian, or a person interested in his/her own health. PHR System's adoption and compliance with international standards is foremost important because it can help to meet international, national, regional or institutional interoperability and portability policies. In this paper, an interoperable PHR System for supporting the control of type 2 diabetes mellitus is proposed, which meets the mandatory interoperability requirements proposed in the Personal Health Record System Functional Model standard (ISO 16527). After performing a detailed analysis of different applications and platforms for the implementation of electronic Personal Health Records, the adaptation of the Indivo Health open source platform was completed. Interoperability functions were added to this platform by integrating the Mirth Connect platform. The assessment of the platform's interoperability capabilities was carried out by a group of experts, who verified the interoperability requirements proposed in the ISO 16527 standard.