GtkD global font size

[Sai via Digitalmars-d-dwt]

I am writing a small GUI application using GtkD3 Builder and 
Glade. On a HD monitor the default font size is too small. The 
adwaita theme is not great but I can live with it.

Is there any way to globally increase the font size in the GtkD?
I tried the settings.ini file, but that did not help with my 
GtkD3 app. On the other hand, it did increase the global font 
size of the Glade tool, just not my application. Is some how GtkD 
different from pure Gtk application?

Thanks in advance.
-Sai