You can cook rice very easily in a pressure cooker. The rice absorbs the limited water, so you do not need to drain anything. This process traps the water-soluble nutrients inside the rice. But we cannot claim that cooker rice is the most nutritious option. The cooker alone does not decide how the rice affects your blood sugar.
The rice variety, starch nature, polishing level, cooking time, and portion size play a massive role here. Studies show that the Glycemic Index or GI value of different rice types ranges from 48 to 93.
For example, long-grain rice like Basmati raises blood sugar much slower than short-grain rice. Some research proves that brown rice has a lower GI than white rice. But this difference can change based on the cooking time and rice nature. Therefore, the claim that cooker rice instantly spikes blood sugar is not entirely true.