Dipeptidyl peptidase-IV or DPPIV is a protein recognised as a biomarker in certain diseases and physiological states. Biomarkers are molecules that indicate physiological states, illnesses and diseases and are used in the diagnosis, prognosis and analysis of the development of a specific state. This protein is in fact associated with processes of the immune system, glucose metabolism, inflammation and cardiovascular regulation and has also been found to function as a mechanism of communication between muscle tissue and adipose tissue. “It is a protein that has enzyme activity, but which at the same time performs other kinds of functions in the body. It has so many functions and such unknown ones that it is very difficult to know exactly which mechanisms regulate it,” explained Dr Begoña Sanz, a researcher in the UPV/EHU’s Ageing On research group.

“Any knowledge provided about the biomarker function of this protein is of interest, because, given the range of functions it performs, it could turn out that if treatment is applied from one of these points of view, it could generate a problem in other circumstances in which it also interferes,” asserted Sanz. In this respect, the doctor highlights the importance of the results obtained in a study conducted by members of the UPV/EHU’s Ageing On research group and of the CITA Alzheimer Foundation on an apparently healthy population of adults. “Most of the current publications on this enzyme refer to its changes in various diseases, but there are very few studies that have explored the correlation of this enzyme with specific parameters in an apparently healthy population.”

Differences in terms of age and sex

The study was conducted on a total of 374 adults (between the ages of 40 and 85). Individually, sociodemographic data were gathered from them, all their anthropometric variables were measured (weight, height, body mass index, etc.), a physical activity study was made and so was a study of their physical fitness (following the Senior Fitness Test).

Once all the tests had been carried out and all the data correlated with the enzyme activity of the protein measured in the blood, the research team saw “that the enzyme activity is associated with parameters and habits linked to health. In other words, the people who have healthier lifestyles, who undertake more physical activity, who are in a better physical state and who have fewer obesity indicators have greater enzyme activity”, specified Dr Sanz. “All this indicates that the activity of this enzyme could be used as a biomarker of the state of health.” In addition, enzyme activity was found to be higher in women than in men “to a fairly significant extent”, she said.

The researcher said that “it would be necessary to go on studying this line to see whether, once these data have been added to the rest in the bibliography, the knowledge about this multifunctional protein can be expanded”. Likewise, “the results would need to be examined in greater depth, because on the basis of other available studies we have found that depending on whether one measures the enzyme activity or the concentration of the enzyme, the results and correlations obtained would vary from the point of view of obesity. Just as the correlations vary if the group studied is a group of healthy individuals or a group of people who have some disease. The results also vary greatly depending on the age group analysed. So much precaution needs to be exercised when interpreting the data obtained when they are not compared with equivalent populations”.

Additional information

This study is a small part of another much larger study in which the UPV/EHU’s Ageing On research group and the CITA-Alzheimer Foundation are collaborating. One of the aims of the Ageing On group is to encourage healthy ageing, so it conducts research into and disseminates the benefits of physical activity and healthy lifestyles. The CITA-Alzheimer Foundation for its part has for years been measuring a broad range of parameters among a cohort of healthy adults to be able to retrospectively contrast the association of these parameters with the development of Alzheimer’s.