If the Sun is in Lagna, and Mars is in the 7th, diabetes is indicated.
This is considered as a combination for insanity by some authors. If the Vargas are watery signs, diabetes is likely.

If Mars aspects the 8th house diabetes is indicated.
This has been observed in the horoscopes of many diabetics.

Mercury in the 8th indicates urinary problems.
If Mercury has Vargas in watery signs and is aspected by malefics, the results are strong.

If the Lord of Lagna is in the 6th with Mars, diabetes is indicated.
When the combination is present, untimely diet is indicated. Consequently problems like hyperacidity and ulcer are likely. Because the 6th house is afflicted, diabetes is also likely.

If the Moon’s navamsa is in cancer and Scorpio and the Moon is conjoined with a malefic, disease of a subtle nature is likely.
We get from Brhajjataka of Varahamihira

candre karka av s'cika s'akagate papairyute guhyaruk

The term guhyaruk suggests “one with diseases in secret or subtle parts”. It is to be interpreted using the Vargas of the Moon. If the Moon is in Leo which indicates thirst, hunger etc chances for diabetes are strong.

If a weak Moon is in Leo, thirst, hunger and problems of digestion are indicated, more so when it is an indicator of disease.
When the Moon gets Vargas in watery signs, diabetes is likely.

If a watery planet is in the 7th together with the lord of the 7th, urinary diseases are indicated.
The Moon and Venus are watery planets. When the planets are in watery signs and get Vargas in watery signs, the results will manifest well.

If the lord of 6th is in the 3rd diseases near the navel are indicated.
The place being navel, urinary diseases related to diabetes are also likely.

If the Sun, the Moon and Venus are in the 5th, diabetes is likely.
Watery Vargas aggravate this.

Rahu in the 7th causes diseases of the waist.
This can indicate diseases in the inner part and hence diabetes.

A malefic in the 5th causes problems.
Since the 5th represents pancreas, diabetes is likely. Watery Vargas aggravates this.

If the lord of the 7th is in a malefic’s house and is aspected by a malefic, diabetes is likely.
This is found to be true from observations.

If the Lagna is aspected by Saturn and the weak lord of the 8th has the aspect of a malefic, problems due to indigestion are likely.
This can suggest diabetes also.