Impact of Glucose Loading on Variations in CD4+ and CD8+ T Cells in Japanese Participants with or without Type 2 Diabetes

Objective: The aim of this study was to examine the fluctuations in CD4+ T cells, CD8+ T cells, and natural CD4+CD25+FoxP3+T-regulatory (Treg) cells following an oral glucose tolerance test (OGTT) in participants with and those without type 2 diabetes (T2DM). Methods: 19 Japanese participants with T2DM (DM group) and 21 participants without diabetes (non-DM group) were recruited and underwent a 75-g OGTT. The cell numbers of leukocytes, lymphocytes, and the T cell compartment, such as CD4+, CD8+, and Treg, were calculated for blood samples obtained after an overnight 12 h fast and during a 75-g OGTT at 60 and 120 min. Results: Before glucose loading, no differences in the cell numbers of leukocytes, lymphocytes, CD4+, CD8+, and Treg were observed between the DM group and the non-DM group. The proportion of CD8+ was significantly reduced, whereas the proportion of CD4+ was significantly increased, after 120 min of glucose loading in both groups. The proportion of Treg was not affected. Furthermore, a significant positive correlation was observed between the AUC0-120 min of CD8+ and the change in the free fatty acid level following the OGTT (ρ = 0.39, P < 0.05), but not that of glucose or insulin. Conclusion: The proportion of CD4+ T cells was increased and that of CD8+ T cells was reduced after glucose loading in both subjects with and without diabetes. These findings suggest that glucose loading dynamically affects the balance of the circulating T lymphocyte subset, regardless of glucose tolerance

Usefulness of the octreotide test in Japanese patients for predicting the presence/absence of somatostatin receptor 2 expression in insulinomas

We investigated the relationship between the results of the octreotide test and somatostatin receptor (SSTR) 2 expression in insulinoma patients, to evaluate the usefulness of this test for predicting SSTR2 expression in insulinomas in Japanese patients. Five females and one male were included in the study. All patients underwent the octreotide test before the surgery carried out to resect the tumor, and histopathological examination of the resected tumor was performed by a single experienced pathologist. SSTR2 expression was evaluated by the SSTR2 immunohistochemistry scoring system. Insulinoma was clinically diagnosed and surgically resected in all six patients. In the octreotide test, suppression of insulin secretion was sufficient after loading in patients 1-4 and 6. In patient 5, however, the suppression of insulin secretion was insufficient, which resulted in severe hypoglycemia with endogenous relative hyperinsulinemia after the octreotide loading. The histopathological findings revealed SSTR2 expression in the insulinomas of patients 1-4 and 6, but not in the insulinoma of patient 5. In conclusion, improvement of hyperinsulinemic hypoglycemia by octreotide in Japanese insulinoma patients was associated with SSTR2 expression in the tumor. Our results suggest that the octreotide test could be useful for predicting SSTR2 expression in the tumor

table_3.doc

Objective<p>The aim of this study was to examine the fluctuations in CD4⁺ T cells, CD8⁺ T cells, and natural CD4⁺CD25⁺FoxP3⁺T-regulatory (Treg) cells following an oral glucose tolerance test (OGTT) in participants with and those without type 2 diabetes (T2DM).</p>Methods<p>19 Japanese participants with T2DM (DM group) and 21 participants without diabetes (non-DM group) were recruited and underwent a 75-g OGTT. The cell numbers of leukocytes, lymphocytes, and the T cell compartment, such as CD4⁺, CD8⁺, and Treg, were calculated for blood samples obtained after an overnight 12 h fast and during a 75-g OGTT at 60 and 120 min.</p>Results<p>Before glucose loading, no differences in the cell numbers of leukocytes, lymphocytes, CD4⁺, CD8⁺, and Treg were observed between the DM group and the non-DM group. The proportion of CD8⁺ was significantly reduced, whereas the proportion of CD4⁺ was significantly increased, after 120 min of glucose loading in both groups. The proportion of Treg was not affected. Furthermore, a significant positive correlation was observed between the AUC_{0–120 min} of CD8⁺ and the change in the free fatty acid level following the OGTT (ρ = 0.39, P < 0.05), but not that of glucose or insulin.</p>Conclusion<p>The proportion of CD4⁺ T cells was increased and that of CD8⁺ T cells was reduced after glucose loading in both subjects with and without diabetes. These findings suggest that glucose loading dynamically affects the balance of the circulating T lymphocyte subset, regardless of glucose tolerance.</p

table_1.doc

Objective<p>The aim of this study was to examine the fluctuations in CD4⁺ T cells, CD8⁺ T cells, and natural CD4⁺CD25⁺FoxP3⁺T-regulatory (Treg) cells following an oral glucose tolerance test (OGTT) in participants with and those without type 2 diabetes (T2DM).</p>Methods<p>19 Japanese participants with T2DM (DM group) and 21 participants without diabetes (non-DM group) were recruited and underwent a 75-g OGTT. The cell numbers of leukocytes, lymphocytes, and the T cell compartment, such as CD4⁺, CD8⁺, and Treg, were calculated for blood samples obtained after an overnight 12 h fast and during a 75-g OGTT at 60 and 120 min.</p>Results<p>Before glucose loading, no differences in the cell numbers of leukocytes, lymphocytes, CD4⁺, CD8⁺, and Treg were observed between the DM group and the non-DM group. The proportion of CD8⁺ was significantly reduced, whereas the proportion of CD4⁺ was significantly increased, after 120 min of glucose loading in both groups. The proportion of Treg was not affected. Furthermore, a significant positive correlation was observed between the AUC_{0–120 min} of CD8⁺ and the change in the free fatty acid level following the OGTT (ρ = 0.39, P < 0.05), but not that of glucose or insulin.</p>Conclusion<p>The proportion of CD4⁺ T cells was increased and that of CD8⁺ T cells was reduced after glucose loading in both subjects with and without diabetes. These findings suggest that glucose loading dynamically affects the balance of the circulating T lymphocyte subset, regardless of glucose tolerance.</p

table_4.doc

Objective<p>The aim of this study was to examine the fluctuations in CD4⁺ T cells, CD8⁺ T cells, and natural CD4⁺CD25⁺FoxP3⁺T-regulatory (Treg) cells following an oral glucose tolerance test (OGTT) in participants with and those without type 2 diabetes (T2DM).</p>Methods<p>19 Japanese participants with T2DM (DM group) and 21 participants without diabetes (non-DM group) were recruited and underwent a 75-g OGTT. The cell numbers of leukocytes, lymphocytes, and the T cell compartment, such as CD4⁺, CD8⁺, and Treg, were calculated for blood samples obtained after an overnight 12 h fast and during a 75-g OGTT at 60 and 120 min.</p>Results<p>Before glucose loading, no differences in the cell numbers of leukocytes, lymphocytes, CD4⁺, CD8⁺, and Treg were observed between the DM group and the non-DM group. The proportion of CD8⁺ was significantly reduced, whereas the proportion of CD4⁺ was significantly increased, after 120 min of glucose loading in both groups. The proportion of Treg was not affected. Furthermore, a significant positive correlation was observed between the AUC_{0–120 min} of CD8⁺ and the change in the free fatty acid level following the OGTT (ρ = 0.39, P < 0.05), but not that of glucose or insulin.</p>Conclusion<p>The proportion of CD4⁺ T cells was increased and that of CD8⁺ T cells was reduced after glucose loading in both subjects with and without diabetes. These findings suggest that glucose loading dynamically affects the balance of the circulating T lymphocyte subset, regardless of glucose tolerance.</p